A pregnancy test is a test that determines whether or not a woman is pregnant. There are two main types of pregnancy tests: urine and blood tests. Pregnancy tests work by detecting levels of the hormone called human chorionic gonadotropin (hCG), which is a hormone that is produced when a fertilized egg attaches to the wall of a woman's uterus.
Urine based pregnancy tests are available in the form of at-home tests and in doctors' offices. Although urine tests are private and convenient, they may not always be accurate. They cannot be used too early in a pregnancy. Blood based pregnancy tests can detect pregnancy as early as six days after ovulation, but results take longer to receive than urine tests. Blood based pregnancy tests are generally done by doctors or in other environments that offer birth control and other services in the family planning sector.