Kits that can be purchased without a prescription to help diagnose pregnancy. Home tests are similar to the pregnancy tests performed by doctors, but the results may not be as accurate. Several different types of home pregnancy testing kits are available; they all involve the detection of a hormone called HCG (human chorionic gonadotropin) in the woman’s urine. HCG is produced in large quantities by the developing placenta during the first few weeks of pregnancy and is evident in the woman’s urine.