I am 18 and I have not had a period since April. I was wondering if anyone had any suggestions as to what might be wrong. Also I recently had sex and was wondering if it is a possibility that I'm pregnant even though I didn't have a period for 3 months before.

This does not mean you are not pregnant, but no period before sex does not have anything to do with pregnancy.

There are hormone issues, infections, and other problems, a trip to you doctor is called for