But if you are going to be sexually active, do not carried away, or as you realize, you could realize another statistic. And I'm sure at this age you don't want a baby or an abortion. That's a great side effect. Talk to your doctor, and read about this in my book Girltalk. Your Sister Never Told You.
Side effects vary depending on the girl.
Well, if you like her, don't keep it a secret. Then, gauge her response. Girls this advice works in the other direction too. I was 15 when I started my period. That means that for every 10 or 11 year old who gets her period, there is a 14 or 15 year old.