Here's How Early You Can Take A Pregnancy Test — And Get Results You Can Trust

When you're eager to know if you're pregnant, waiting feels excruciating. As tempting as it may be to take the test before a missed period, taking at-home pregnancy tests too early can render them useless. That's because home pregnancy tests work by detecting the "pregnancy hormone," human chorionic gonadotropin (hCG). Your body only produces hCG after a fertilized egg has implanted in the uterus, which happens around 10 days after conception. However, while the rule has been to wait until after your missed period to take a home pregnancy test so your body has enough time to produce detectable levels of hCG, many at-home tests can identify hCG even earlier. In fact, some early detection pregnancy tests can tell you if you're pregnant up to six days before your missed period. 

But before you mark your calendar, there are a few things to consider. First, hCG levels increase rapidly with time — doubling every few days. So while early detection tests are more sensitive and can detect lower levels of hCG, the earlier you take a test, the higher the chances of a false negative. Early detection tests only claim 99% accuracy from the day of your expected period, with accuracy percentages decreasing the earlier you test. The First Response brand website, for example, states that its Early Result Pregnancy test is 96% accurate four days before an expected period, and 76% accurate five days before. So a negative result with an early detection test does not definitively mean you aren't pregnant. If you miss your next period, test again. 

Wondering whether you're pregnant is stressful enough without questioning whether your at-home pregnancy test results are accurate, so it's worth taking a few simple steps to ensure the most reliable results. First and foremost, inaccurate results are frequently user-error, so make sure you take the test properly, carefully reading and following the instructions. It's also important to make sure you understand how to interpret the results. Always read the test in the allotted time window as stated in the instructions. Checking the test too early can give you a false negative. If you wait too late, an evaporation line can appear on the test as your urine dries, which can be mistaken for a positive result when you aren't pregnant. (Evaporation lines are usually colorless while the actual test lines have a color dye, which can help clear up confusion, but it's still best to discard a test after the time window expires.)

While waiting until later in your cycle to test will provide more accurate hCG detection, the best time of day to take the test is first thing in the morning. That's when hCG levels are the strongest and therefore the easiest to detect. At other times of the day, waiting at least three hours since your last bathroom visit is best. Of course, irregular periods can make detecting hGC more complicated. If your cycle isn't regular, you can take a pregnancy test three to four weeks after intercourse. False positives are far less likely than false negatives, but they can occur if you take medication containing hCG as an active ingredient, like certain infertility medications. In that case, it's best to consult your healthcare provider about when and how to test for pregnancy.