Seeing is believing, and nothing is as definitive as a seeing that positive result on your home pregnancy test. These tests work by detecting the hormone hCG, produced by the placenta, and found in a woman's urine. They're over 99 percent accurate when the instructions are followed carefully.
"Home pregnancy tests are comparable [in accuracy] to urine pregnancy tests used in clinical settings when used properly," wrote certified nurse-midwife Regis [source: Regis].
Though uncommon, it's still possible for the test to be wrong and show a false-negative or false-positive result [source: Mayo Clinic]. If you've taken more than one home pregnancy test and gotten conflicting results, the Mayo Clinic recommends making a doctor's appointment.
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