I haven't had a period in 4 months. I went to the Dr. and she prescribed prometrium it worked for 2 months and now I'm back to not having a period. The dr swears it's a hormone thing but is this a common problem. Prior to this I was on the patch for birth control while taking acutane for acne. Does this have anything to do with it? My husband and I really want to have a child in 2011. *** help..