Pregnancy tests work by checking your urine (pee) for a hormone called human chorionic gonadotropin (HCG). Your body only makes this hormone if you’re pregnant. HCG is released when a fertilized egg attaches to the lining of your uterus— when pregnancy begins. If your pregnancy test results are positive, it means you’re pregnant. If they’re negative, it means you’re not pregnant. Pregnancy tests are most accurate when you take them after you’ve already missed your period.
Pregnancy tests are super accurate when you use them correctly. The pregnancy tests you get at the drugstore work 99 out of 100 times. They’re just as accurate as a urine pregnancy test that you’d get at a doctor’s office.