Pregnancy tests work by checking your urine (pee) for a hormone called human chorionic gonadotropin (HCG). Your body makes this hormone if you’re pregnant. HCG is released when a fertilized egg attaches to the lining of your uterus — when pregnancy begins.
How soon can I take a pregnancy test?
You can take a pregnancy test anytime after your period is late — that’s when they work the best. It’s a good idea to take a pregnancy test as soon as possible if you miss your period or think you might be pregnant.
Sometimes a pregnancy test is able to find pregnancy hormones in your urine as early as 10 days after unprotected sex. But these results aren’t super reliable, and you may get a false positive or false negative test result.
If your periods are very irregular, or you don’t get periods at all for one reason or another, your best bet for accurate results is to take a pregnancy test 3 weeks after sex.