Pregnant or Not? How To Know

Medical Author: Medical Author: Melissa Stoppler, M.D.
Medical Editor: Barbara K. Hecht, Ph.D.

To learn whether you are pregnant or not, a pregnancy test may provide you with the answer. This test can be done in the privacy of your home using one of several available test kits. Or the test can be performed in your doctor’s office or clinic. Home pregnancy tests are always done on urine while those in a doctor’s office or clinic may be done on urine or blood.

All pregnancy tests are based upon measurement of the same hormone -- human chorionic gonadotrophin or hCG -- which is only present in a woman when she is pregnant. This hormone is made after the egg is fertilized and its levels rise rapidly in early pregnancy. It acts to support progesterone, a hormone necessary to maintain the pregnancy.

Most home pregnancy tests are done because of a missed period. If a woman has regular menstrual cycles, a home test can be very informative. It can tell whether or not there is a pregnancy as early as the first day of the missed period (which is about two weeks after conception).

Manufacturers of home test kits claim that their kits are 97%-99% accurate, but the sensitivities of different test kits depend on the levels of hCG in the urine required for a positive result. If your test result is positive, see your healthcare provider promptly.