I have missed my period for 2 or 3 months and then it came back in August and now I missed it again in September. I am 17 years old

When did you first get your period? Has it always been like this?

My periods have always been like this. Ill have one every 2 months and it will stay medium flow for about 2 or 3 days and then go away.

Sometimes birth control can regulate you.

Doctors will often recommend birth control to regulate girls whose flows are not regular. However, usually there is a deeper problem. Many over weight women experience this from pubescent years to menopause. Certain a poor diet and large amounts of stress can influence it also. My girlfriend had a problem when she went to college because of the lack of exercise.