Have you ever heard of the marshmallow test? Researchers told kids they could have one marshmallow now, or two marshmallows later. It’s supposed to have big implications for later in life; the kids who practiced delayed gratification had lower divorce rates, higher SAT scores, lower rates of addiction, and so forth.
Well, I’m a “one marshmallow now” kind of girl, at least when it comes to taking pregnancy tests. Wait until tomorrow morning so I can test with the first urine of the day? Nah, let’s do this now! And maybe again in a few hours! Luckily, I can use my HSA to pay for pregnancy tests, or I’d be in big trouble with my husband.
So when I finally, finally saw a teeny tiny faint blue line on my pregnancy test (especially if I held it at a 45° angle to my bathroom light), I was pretty excited. My husband was a bit more skeptical. He agreed that maybe there was a faint line on the pregnancy test, but he wasn’t convinced. Naturally, I dove into the research.
How Pregnancy Tests Work and What a Faint Line on a Pregnancy Test Means
A pregnancy test detects the amount of human chorionic gonadotropin (hCG) in urine. The most sensitive tests can detect as little as 15 mIU/ml of hCG. If you’re testing a few days before your expected period, you should use a more sensitive test. For the record, I was using the CVS Early Result Pregnancy test, which detects 25 mIU/ml of hCG.
Women who are not pregnant usually have 1-5 mIU/ml of hCG in their urine. After conception, hCG levels double every 48 hours. If you test too early, you’ll get a negative result because your hCG levels aren’t high enough. Wait a few days and test again (using your first morning urine, if possible).
False-negative results can happen if you take the test too early. But a false positive is much less likely. If the test detects higher levels of hCG in your urine, there is a 97% chance that you are pregnant, regardless of how faint that line on the pregnancy test looks.
If you do get your period a few days later, you may have had a chemical pregnancy. This is another name for a very early miscarriage; the American Pregnancy Association estimates that 50-75% of miscarriages are chemical pregnancies.
What Do My Pregnancy Test Results Mean?
If you’ve gotten a positive pregnancy test result (even a very faint one), you are probably pregnant. Just make sure you’ve followed the directions on your pregnancy test. Don’t try to read it after ten minutes since the urine can leave an evaporation line as it dries, which can look an awful lot like a positive result. If you’re still not sure, take a page from my husband’s book: he went out and bought a digital pregnancy test. It was hard to argue with that big, bold ‘YES’ in the window.
If your pregnancy test is negative and you took it on or after the day of your expected period, you are probably not pregnant. But if you’ve taken the test early, it’s possible that you could be pregnant and your hCG levels just haven’t increased to a detectable level. Here’s what you can do:
- Wait a few days and then take another pregnancy test using the first morning’s urine.
- Try a more sensitive pregnancy test, which will detect lower levels of hCG.
- Wait and see if you get your period, and then take another test.
Remember how I said I was the “one marshmallow now” kind of girl? That’s a bad strategy in pregnancy testing and life in general. You will end up buying a bunch of pregnancy tests and then discounting any negative results because it “might be too early.” If you can hold out, wait until the day of your missed period. You can buy a $1 test that detects 50 mIU/ml of hCG at Dollar General (but they hide them behind the counter, so you have to ask). If you can wait, do. It will save you money and heartache if you haven’t yet conceived.
Now, excuse me while I hunt down some marshmallows…