Pregnancy tests are used to detect the presence of human chorionic gonadotropin (hCG) in urine or blood. hCG is a hormone produced by the placenta during pregnancy. Pregnancy tests can be performed at home or in a doctor’s office. Home pregnancy tests are typically urine tests, while doctor’s office pregnancy tests can be either urine or blood tests.
Pregnancy tests are very accurate, but they can sometimes give false positive or false negative results. False positive results can occur if the test is taken too early in pregnancy or if the test is performed incorrectly. False negative results can occur if the test is taken too early in pregnancy or if the hCG levels in the urine or blood are too low to be detected.