How accurate are pregnancy test strips?
Disease description:
My period is already four days late this month. Today, I used a home pregnancy test, and it showed two lines—however, one line is very faint. Could this be a false positive? What is the accuracy rate of such tests?
Doctor's answer (1)
Dr. Luo Xin
When used correctly according to the manufacturer’s instructions after a missed menstrual period, early pregnancy test strips have an accuracy rate exceeding 80%. These test strips primarily detect the concentration of human chorionic gonadotropin (hCG) in urine to determine pregnancy status. hCG levels typically become detectable in urine approximately 10 days after conception. However, testing too early or using improper technique may yield negative or faintly positive results. In such cases, retesting after a few days—checking for a clearly positive result—is recommended.
