A home pregnancy test is simple to do and can give you an accurate answer in 2 to 5 minutes.

Improved technology has made the urine home pregnancy test about as accurate as blood tests--99 percent under perfect conditions--although in actual use it may be less than that.

Using a woman's urine, a home pregnancy test detects the presence of human chorionic gonadotropin (hCG), a hormone produced only during pregnancy. The tests contain monoclonal antibodies, which are molecules coated with a substance that bonds to the pregnancy hormone. If the hormone is present, a colored stripe, dot, or other symbol appears in the test windows. The tests also contain "control" windows to indicate whether the device has functioned properly.

Although the makers of today's tests say their products can detect hCG as soon as the very day a missed period was supposed to begin, they also advise taking the test again a few days later to confirm the result. If the result is positive, see a doctor as soon as possible.