The first signs of a girl getting her period are breast development, pubic hair growth and clear discharge, according to TeensHealth. Breast development is one of the first signs of puberty in girls, beginning about two to two and a half years before a girl gets her first period.
A girl might notice a clear or whitish discharge a few months before her first period, reports BeingGirl.com. The average age for a girl's first period is between 13 and 14, but it could occur at any time between the ages of 8 and 16. A girl over 16 years of age who hasn't had her first period should visit her doctor.