Period stopped and won't start back up
I'm 15 years old almost 16 in less than 2 months. I started my period when I was 12. Around when I was turning 13 to 14 my period stopped for a while then would start for about 3 days then it was over again. Well pretty soon it just stopped and I would have no signs of having a period. I went to see a doctor he did blood work but I never got the results so I went to a new doctor and she put me on birth control. She told me that the birth control should regulate my period but it hasn't. My question is should I worry or just relax and keep taking the birth control and will I ever be able to get pregnant?