Why Taking a Pregnancy Test Too Early Can Lead to Inaccurate Results (2024)

Pros of early pregnancy tests

Early detection pregnancy tests may offer advantages in some circumstances. But you may want to discuss your testing plans with your health care provider first. They can advise you on the accuracy and whether it's needed in your situation.

Early detection

Aside from having a physician order an earlyhCG blood test—which is usually done for medical reasons—early home pregnancy tests are the fastest way tofind out whether you're pregnantduring a particular menstrual cycle.

The most sensitive tests on the market can potentially give you a positive result four to five days before your period is due. This means you don't necessarily have to wait for amissed period, or watch for otherearly pregnancy symptoms, to find out whether you're expecting.

However, there's a significant chance of getting a false negative with early pregnancy tests. This happens when the test says you're not pregnant but you really are. That's because your body might not be making enough pregnancy hormone (hCG) to trigger a positive result just yet.

Medication changes

Very early testing can be helpful if your physician wants you to start or discontinue anymedicationsas soon as you discover you're pregnant. That said, they may recommend blood testing instead of an at-home early pregnancy test due to the risk of getting a false negative.

Birth control failure

Early pregnancy tests may also be helpful if you werenotintending to conceive but had a birth control failure around the middle of your cycle. In these situations, it's understandable that you want to know as soon as possible whether you're pregnant so that you can determine your desired course of action.

If you're sure you don't want to get pregnant, emergency contraception is a sound option. As long as it's taken within 72 to 120 hours after birth control failure (depending on the brand or method), emergency contraception can prevent implantation entirely. Talk to your health care provider about this option.

Pregnancy lifestyle changes

A common reason to choose early pregnancy testing is starting prenatal care. This includes focusing on eating well, takingprenatal vitamins, and avoiding alcohol. If you think you might be pregnant, it might be wise to forgo the early testing altogether (which could give a false negative result) and make necessary lifestyle changes now, just in case. Many people who are trying to conceive will have already made these lifestyle modifications.

Cons of early pregnancy tests

For the most accurate results, experts don't recommend taking an early pregnancy test. Rather, they advise waiting until you miss your period. Here are some other potential downsides of early testing.

False negatives

The package insert for one of the leading brands ofearly pregnancy testsstates that, when used five days before the expected menstrual period, the test will detect hCG in about 76% of pregnant people. Four days before the expected menstrual period, 96% of people will have a positive result if they're pregnant—meaning 4% may not.

Although very early tests can indeed say that youarepregnant in a given cycle, they can't tell you that you're definitelynotpregnant. And there's a significant chance of having afalse negative result before you miss your period.

Cost of repeated testing

You're more likely to get a false negative result if your menstrual cycle varies in length or if you're not tracking your period. Additionally, if you take a test when your urine is diluted rather than concentrated, it can throw off your results.

The uncertainty of a negative result may lead you touse multiple early pregnancy testsin each menstrual cycle, and this practice can cost you a considerable amount of money without changing the ultimate answer.

Chemical pregnancy

Early pregnancy testing increases your chance of detecting very early miscarriages that might otherwise go unnoticed. Often termed "chemical pregnancies," these miscarriages cause you to get a positive pregnancy test but then have your period arrive on schedule or only a few days late, making the test appear to be a "false positive."

Researchers believe thatchemical pregnanciesare extremely common and rarely indicate any underlying health concerns in the pregnant person. But these conceptions are being detected more often because of the sensitive pregnancy tests now on the market.

If you wait to test until after your period is due, you will lower your odds of noticing a chemical pregnancy. Depending on your outlook, you may prefer to wait to take an early pregnancy test to reduce the risk of being disappointed a few days later.

Anxiety

Perhaps the biggest drawback of early pregnancy tests is the anxiety associated with them. While we think of anxiety as primarily a mental health symptom, the resulting stress hormones can also be physically unhealthy.

Positive Early Pregnancy Test

If you get a positive result from an early test, you should contact your health care provider as soon as possible. Your OB-GYN can confirm the pregnancy, and together you can discuss the next steps.

Usually, these include dietary and lifestyle changes, as well as adding prenatal vitamins to your regimen. You also should discuss any health or medical issues with your provider.

False positive results are rare and usually only occur if you take the test shortly after a miscarriage or pregnancy loss. They also can occur if you've recently taken fertility medication containing hCG.

Negative Early Pregnancy Test

If you have a negative early pregnancy test but still think you might be expecting, wait several days and test again. You can also contact your health care provider and schedule an in-office test. Some medical conditions can result in negative results, so mention any symptoms you're experiencing to your provider so they can rule out an ectopic pregnancy or other complications.

If you're actively trying to conceive, consider using an ovulation test or monitoring fertility signs (like basal body temperature and cervical mucus) to determine when to have intercourse. You can also use an ovulation calculator. In general, ovulation occurs 14 days before your next period is due.

False negatives are more common than false positives, and they can happen if you test too early in your pregnancy and hCG hasn't built up to detectable levels yet. False negatives might also occur if you test too late in the day when your urine is diluted. Test as soon as you wake up so hCG has had more time to build up in your urine as you sleep.