I'm 18 and I haven't had my period for 3 months. I don't have sex at all yes I have a boy friend but I don't do any of that with him. In the last past 3 months I had it hard like with boys I had 2 in 3 months -.-. But any way I was just wandering if I should go on to birth control so my periods are regular oh and also I started my periods when I was only 9 so yes. Thanks for the help :) again I'm not pregnant.