I m 20, a virgin , and I know I can t be pregnant. But my concern is that I haven t gotten my period this month, but I ve had all the pms symptoms. I ve broken out for the past week, my breasts have been sore for a few weeks, and I ve been craving carb-y things (which usually happens to me just before my period.) I have started running again semi-regularly (every 2-4 days for the past 3 weeks) and because of my newish medication I ve lost weight ( Adderall , I was 145 and now I m about 125, I m 5 4). I don t think that I m anywhere near underweight , but could it be that the weight loss coupled with my attempt at making running a habit again could have caused my period to be late? Is there another reason that I should be concerned about?