I had this for years, since about age 15. I am now 22 and having regular periods since last september. After seeing countless doctors, and being told it will fix with age, to lose weight and it will come back, (I am overweight, but not that overweight), and not to worry about it because I wasn't about to have kids anytime soon...Finally I went to a gyno, since regular doctors didn't seem to care. This guy was angry that no one had been concerned about it...and he immediately sent for ultrasounds (I have had about ten altogether before this guy) and bloodtests. He said the funniest thing- when I think about it now..."what did they want, to hand you an envelope with cancer in it? Thats whats going to happen if they don't fix this". That made him my favourite doctor- and he also fixed many other medical problems I had been having. So I went on progestin for ten days- provera- a female hormone. I started BCP's right after that, and had my first period since age 15. It was so exciting! (and PAINFUL!!!) Anyway, I would go to a gyno, not to your reg doctor. I find them to be mroe helpful. Good luck!! And research stuff yourself, but DON'T look into things too seriously until you have confirmed it with a professional.