Suggest Treatment For Thin Endometrial Lining And Irregular Menstruation

Hi there. I started my period when I was 12 and I m now 18, still with irregular periods. I sometimes go more than 8 months without a period. I was on birth control for about 6 months 2 years ago, and that seemed to help. However, once I was taken off, my periods became irregular again. I recently visited a gynecologist and he did a sonogram and blood work to check for any causes for concern. He said everything looked good except the liner around my uterus is somewhat thin. He prescribed me Naproxen Sodium, Estradiol, and Medroxyprogesterone to take for the next month. After reading over the effects and uses, I m concerned this method might be a little too aggressive for my age and situation. I m not trying to get pregnant right now, so I don t know why we need to be this aggressive at this point. Would birth control not be a better route to go in regards to a less aggressive form of treatment? I will be meeting with my doctor tomorrow to discuss my concerns, but I would really appreciate a second opinion. Thank you!