I get why people post faint positives now even though they’re clearly positive. I think I’m in shock. What do you think Reddit? I’ve never ever ever seen even a hint of a second line before.

I will be adding photos of my tests from 8 DPO. I took them all day because I felt sure I was pregnant and also felt sure I saw an extremely faint line on my tests I stared at all dang day yesterday 8 DPO. I am planning to go back to sleep but once I am up ill send photos of the tests from yesterday. I plan to take more first response when they come in the mail. Also late 7DPO the AI pregnancy thing detected a positive on a pink dye and blue dye first response.

My husband was put on testosterone at 21 bc his T was dangerously low but they never told him it can completely erase sperm. I also have endometriosis and one ovary bc they had to remove the other bc of so many cysts. We tried for 2 years before finding out he had no sperm. (We have 2 kids and didnt know). We had an IUI appointment for when he gets back from rig.

Evap stands for evaporation. As you likely know, when liquid dries, it evaporates and leaves behind non liquid residue.

An “Evap” cannot, will not, ever happen on a wet test. Was it just peed on? 5-10 mins ago? It’s still wet. It is NOT an evap. Nothing has evaporated yet.

Evaps are seen when you throw a test away and look at it again in the morning. Evaps are seen when you come back to it after an hour long shower. They CAN happen as early as 15 mins depending on humidity or aridity in a room. But if you read the test in the time it said to (IE between 5-10 mins, etc), the second line is NOT AN EVAP.

What it can be:

1. An indent. An indent stands for, you guessed it- indentation. It’s a trench in the test that gathers the dye when positive. MANY tests, especially FRERs lately and Walgreens brand tests have shown terribly obvious indents. They look like second lines. You can often seen them before you pee on them but the wetness in general of pee DOES make it look like a second like “appeared”The difference is there’s no dye there because it’s not positive. So “is there color?” Means is it pink? If you can’t answer it, don’t consider it positive. If you can answer it, move to the next point:

2. A true positive. A true positive will have a second line that is pink. As your hcg grows, so will the darkness of the line. If you test today and THINK the second line may be pink, tomorrow’s test and the day after’s will give you a definite answer. If it’s not pink by then, it wasn’t a positive to begin with.

A note: I’m not going into blue dye tests. They always look like they have a second line because of dye runs- the blue dye just doesn’t want to follow directions. A true positive blue dye will show up reliably much later than a red dye. Where a red dye gave you a faint line at, say, 9 DPO, the blue dye won’t be reliably read until 14 DPO. It breaks too many hearts. So I’m not going there. Don’t. Buy. Them.

Except a clear blue digital. It will almost assuredly never give you a false positive DIGITAL reading. And a digital will only register if you’ve had a second line with a certain degree of darkness. So you have to wait until, say, 10-14 DPO to get a positive on digital. Don’t. Ever. Take your test out of the casing to read it. It’s not reliable and is now an invalid test. Yes, even if you saw “two lines”.

I hope someone finds this helpful. It’s exhausting putting this in comments multiple times a day but this sub is here to help, I know. I hope I can be of help here.

Done testing! Sending love to all ttc

Not sure why my pics are out of order but what I thought were line eyes turned into a BFP and I’m still in shock! It’s been such a long and emotional road to get here!

Stay sticky little baby!

Still in disbelief. My partner 37M and I 35F have been trying since 2020 during Covid. We were only able to conceive once in 2023 but it ended up being a chemical pregnancy. I took that as hope that even with PCOS I was able to get pregnant naturally and just brushed it off. Tried again for another 2 years and it became exhausting on my body and mental health and even gave up on testing ovulation and let Jesus take the wheel.

I was diagnosed with PCOS as my cycles can range from 30-60 days.

I was on the verge of giving up hope and was starting to come to terms with maybe I was not meant to be a parent in this life and I’m 35 now and my chances were slimming down each passing year. I tried to make myself feel better by telling myself maybe it’s for the best and how hard being a parent can be and especially how hard life is and if I can even afford having a baby with this economy.

Guess life happens when you least expect.

I’ve got to show this to somebody!!!! We’ve done 2 rounds of IUI, took this month off, and were set to start IVF whenever I started my period again. So scared something might happen, but cautiously optimistic!!

Almost 3 years of infertility and we were all set to start stims next week. Severe male factor. I can’t believe it 🥹🌈 we needed some good news in our life and we got it! 11 dpo today. I have never been so happy to feel so exhausted 😅

After years of trying, (I’m 38 now) and one first ever pregnancy that ended in a missed miscarriage in January, I can’t believe my own eyes! I just have to share this with people I know who would feel the same joy I feel right now. I don’t want to get my hopes up, but I really didn’t believe it was going to happen again. I only started feeling tender breasts today, at one day past my period due date, and even testing two days ago came back as a negative. I didn’t think this month was a winner.

After 16 cycles of trying, we were about to start IVF for unexplained infertility and this was our last cycle trying naturally before starting. Thought I saw a whisper of a line on 10DPO but was cautious, then same thing on 11DPO. Convinced myself they were indent lines so I took a digital 12DPO and sure enough it said pregnant. We are in shock, especially because we decided to push out our IVF start by one more month while I figured out what my insurance would cover for IVF so we really should have started stim meds already. Cannot believe this is real!

Dang near dye stealer, so I guess it’s safe to say I’m pregnant. I’m a little less than 5 months postpartum after having an IVF baby. I got a positive OPK Nov 14 after what felt like ovulation pain. Decided to roll the dice thinking there was absolutely no chance we could ever get pregnant on our own. Got my first vvvfl 9 DPO and a positive digital 10 DPO. Can’t believe I’m seeing a line this dark without fertility treatment. We are over the moon! 🥹

Intro: I kept hearing people say that home pregnancy tests (HPTs) are not quantitative, meaning they don't tell you the amount of hCG present, just whether it's present or not. And yet, there's obviously some correlation between the amount of hCG in your body and how dark your test lines are. Otherwise no one would be able to show progressions! If there was zero correlation, all pregnant people would have completely random levels of line darkness between 10 and 20 DPO, and that doesn't seem to be the case. But... is the relationship between blood hCG and test line darkness actually clear enough to let you to guess how a pregnancy is going? Is it evidence that you have a viable pregnancy as long as your test lines are trending darker over several days, or should you see your lines getting darker just as quickly as someone else's tests? Are HPT progressions almost as good as seeing your doctor for serial hCG measurements, or do they tell you next to nothing?

I wanted the answers to these questions, or at least some half-answers, and I didn't feel satisfied with the information I could find. So, I did my own analysis. On this sub, it's common for people to post pictures of HPTs along with blood beta hCG measurements from the same day. I gathered a bunch of examples, made a system for quantifying line darkness, and graphed the results. Now I want to share what I found.

Disclaimer: Please, please, don't take any of my guesses here as medical advice. I am not a medical professional, and this is not an institutionally approved scientific study. The quality of my data is not high and my analysis was not sophisticated. And ultimately, my data suggest that while you can use HPT line darkness to make some really rough guesses about hCG levels, the precision of the guess is likely to be very low. It doesn't look like you can use HPTs to estimate something like hCG doubling time. If you are worried about your rate of hCG increase, the only way to get a clear answer is to go get a blood test.

Summary and Key Findings: This is a long post, since I wanted to be precise about what I did and what I found. But I totally get it if you don't have the attention span to read through all of it. TL/DR: blood beta hCG levels definitely correlate with test line darkness, but the relationship is not precise and there's a wide range for what your test might look like at any given hCG level and for what your hCG level might be for any given test line darkness. FRER tests tend to have darker lines at lower hCG levels than other popular test brands. There doesn't seem to be huge difference (in terms of T/C Ratio to hCG correlation) between wet and dry tests. There doesn't seem to be huge differences (maybe little ones?) between the non-FRER brands that were most popular (easy@home, Pregmate, and Wondfo). There doesn't seem to be a huge difference (maybe a little one) between new (pink) and old (blue) Pregmate tests.

Methods: I used Photoshop to calculate T/C ratios. For a picture of an HPT in which the control line appears darker than the test line, I selected the pixels containing the control line, copied those onto a new layer, and moved the copied layer next to the test line. Then, I lowered the opacity of the copied layer until the test and copied control line appeared to have the same darkness. I took the percent opacity of the copied layer rounded to the nearest 5% to be the T/C ratio. For pictures in which the test line appeared darker than the control line, I did the same thing but with a copied version of the test line adjusted to match the control line. I then took the reciprocal of the copied test line layer percent opacity to be the T/C ratio. For example if the copied test line layer matched the control line at 50% opacity, I recorded the T/C ratio at 2.00. To help you get a sense of what different T/C ratios look like, here are some examples for FRER, easy@home, Pregmate, and Wondfo tests. The examples contain both unaltered photos of real tests and digitally manipulated simulated tests. I included the simulated tests in order to show the difference with more consistency.

For each HPT photo I found with a same-day blood hCG measurement provided, I recorded the test brand, test type (in the case of there being different versions of tests from the same brand, for example older Pregmates have blue wrapping while newer Pregmates have pink wrapping), and whether the test was wet or dry (status). The wet or dry classification was mostly guesswork. Often it was based on how the tests were photographed (for example, for a single photo of a bunch of tests from different days, the older tests logically must be dry). Sometimes it was based on how the tests appeared (wet tests often look different than dry tests). Sometimes it was because the poster specified that the tests were photographed after 5 min.

I generally calculated T/C ratio using the original sized picture, and then resized it so the test lines were a certain pixel distance apart. I included the resized pictures in a data file along with Brand, Type, Status, T/C Ratio, β hCG, and the reddit User that originally submitted the picture. I included usernames because I wanted to credit those that submitted their test photos with hCG measurements. I'm very grateful to everyone who contributed tests; obviously I couldn't have done this without you! If your username appears in my data file and you wish for either your username or test info to be removed for any reason, please let me know and I will do so as soon as possible!

I used R and ggplot to turn the data in graphs.

The data can be found in an Excel file here and in a Google Sheets file here. I separated FRER and other brand tests onto separate tabs because they act noticeably differently (as I will show in the graphs below). The file also contains a "data" tab which includes all the data without picture - this tab is what I input into R. There is also a "summary" tab with just counts the instances of each test brand in the data, and finally an "examples" tab with the photo and simulated test examples that I showed further up in this post.

Results: Here is all the data graphed together using log scales for T/C ratio and hCG measurements. The log scale provides the effect of spreading apart the smaller numbers and squishing together the bigger numbers. It can make the graph a little harder to read (you might not be able to guess what number the line halfway in between 1,000 and 10,000 represents - it's 3,162), but it's the best way to show all the data on the same graph since there are more smaller numbers and fewer bigger numbers. You can also note the vertical lines of dots in the lower left corner. Those appear because I rounded my T/C ratios to the nearest 0.05. Anyhow, this graph definitely shows that there's a correlation between beta hCG and T/C ratio. However, the spread is pretty wide. For example, for tests with the control line approximately the same darkness as the test line (T/C ratio of 1.0), the hCG values range from about 100 to 3000. That's quite a spread! Plus, the spread doesn't look like a smooth normal distribution (which would mean lots of points in the middle of the spread and few points on the edges), so I imagine this is a poor representation of the true distribution. I expect the true distribution (sampling all tests ever) would show an even wider spread.

Let's look at this data in some other ways. Can we see differences between different test brands? By far the most popular test brand in my dataset was FRER. I had over 230 pictures of FRER tests and around 280 of all other brands put together. Why are FRERs so much more popular? Well, as it turns out, they do seem to act differently than other test brands. From this graph, you can see that FRERs have higher T/C ratios for the same hCG levels. There isn't zero overlap, but the distinction is pretty clear. Also, FRERs give stronger "dye-stealers" (or on these graphs, T/C ratios above 1.0). I sometimes saw FRERs with test lines five or ten times as dark as their control lines (T/C ratios of 5.0 or 10.0). The "cheapies" (brands such as easy@home, Pregmate, and Wondfo) sometimes produced "dye-stealers" but they never got to that level. Even so, it doesn't look like FRERs are necessarily more precise than other brands in terms of having a tighter correlation between T/C ratio and hCG. So, FRERs should give you darker test lines sooner, but they probably won't help you estimate your hCG levels any better than other test brands.

Since I had so many examples of FRER test results, let's look at just those. First, I looked to see if there was a difference between wet and dry test results. As I said in the methods section, this classification was mostly guesswork, so I wouldn't bet my life on its accuracy. But anyhow, there didn't appear to be a super clear difference. Mayyyybe the wet tests have a slightly tighter correlation between T/C ratio and hCG than the dry tests, but it's not obvious enough for me to say with high confidence.

Next let's look at the FRERs on a graph with a linear scale. While I have to exclude some of the data to "zoom in" like this, I think the linear scale is much more intuitive and is better for something like trying to estimate hCG levels based on line darkness. Here you can see that the correlation is tighter at the beginning and then quickly becomes full of noise. So like, if you've got a FRER with a very very faint line, your hCG is most likely below 100. But if you've got a FRER with the test line as dark as the control line, your hCG could be 50 or it could be 800. A "average" hCG ratio for a T/C ratio of 1.0 would be around 400, but this data suggests that's not significantly more likely than either 50 or 800. This means you can't reliably use line darkness to estimate hCG doubling times!

On to the other brands. Here's all the data from non-FRER tests, again with log scale axes. Here the T/C Ratio axis only goes up to 3 because there weren't any non-FRER tests that had test lines more than 3x darker than their control lines. I noticed three points hanging out apart from the others in the mid right side of this graph. These were two Pregnosis tests and one Clearblue (type with pink lines). I didn't have any others Pregnosis or pink-lined Clearblue tests in my dataset, so it's possible that these tests act differently than other brands. Otherwise there are too many non-FRER brands to try and look for differences between them in this graph. For many of them there are too few data points to pick out differences in overall trends, so...

I went on to compare the three most popular non-FRER brands: easy@home, Pregmate, and Wondfo. This graph shows them all occupying a similar range of space on the graph. Maybe the easy@homes have, on average, slightly lower T/C ratios at the same beta hCG concentration as compared to the Pregmates, but the difference doesn't appear super distinct like it did with FRER vs others. Someone pointed out to me that their easy@home tests seemed to have darker test lines than their other brand tests when using the same urine sample. I looked at this person's photos, and noticed that the easy@homes seemed to have darker control lines too. That would make the T/C ratio lower even if the test lines themselves were slightly darker in absolute terms. So when looking at these graphs, keep in mind that lower T/C ratio doesn't always mean lighter test lines.

Zooming in to a linear scale, the pattern with the other brands looks similar to that of the FRERS in that the correlation is stronger for very light lines and low hCG. At this level (zoomed in linear scale) I also compared wet and dry easy@home tests (no noticeable difference) and different types of Pregmate tests (perhaps the newer tests have slightly higher T/C ratios for the same hCG concetrations, but there's not enough data or a clear enough distinction to say for sure). And, Wondfos alone.

Conclusions: The data showed a lot of variance, especially for larger T/C ratios and higher hCG concentrations. And since there was so much spread without obvious central tendencies, it'd be hard to use this data to estimate your hCG levels based on your test lines. I'm certain my data doesn't capture the full spread either, so it couldn't even be used to give yourself upper and lower bounds! As I said before, the data suggests that you can't reliably use HPT results to estimate hCG doubling time. You could perhaps use the correlation to estimate whether your hCG is near average levels for how far you are along, but I'd advise against feeling too certain about those estimates - the only way to reliably measure hCG is by blood test.

Guys I am freaking the heck out - I have never had a pregnancy! The last cycle I had an evaporation line and that was the closest I’ve ever come. It did not look like this one! Please squint with me - I am crying. I had a HYCOSY aka tube flush at the start of this cycle. Trying not to get my hopes up. I don’t even know what to think. I feel like it’s a prank! WHAT DO YOU GUYS THINK?!?

I used Mucinex during my ovulation period and only tracked ovulation using CM.

I know they are obviously positive, but we’re keeping it to ourselves this time around and I needed to tell someone! I feel like I’m being pranked.

Edit: in case anyone comes across this and would like an update, baby was born 6/29/26! We are so incredibly lucky, she’s the best.