D.B.
I agree with Geneva. Your description is vivid and would be helpful for your doctor. Make notes of when this occurs with respect to your period - before, during, after? If you aren't recording your periods on a calendar, start. And pediatricians deal with teen girls so don't hesitate to go in to the doctor you already have, if you don't have a gynecologist. You should be in the room without your parent(s) at this stage in your life. Be honest about everything. Don't wait for your regular annual check-up - no point in delaying if that's a ways off.