Amenorrhea (the Absence of Periods)
Girls who haven't started their periods by the time they're 15 years
old or 3 years after they've shown the first signs of puberty have
primary amenorrhea, which is usually caused by a genetic abnormality, a
hormone imbalance, or a problem with the way the reproductive organs
developed. Hormone imbalances also can lead to secondary amenorrhea, which is
when a girl who had normal periods suddenly stops menstruating for more
than 6 months or three of her usual cycles.
Since pregnancy is the most co