OK. I'm 33 this year and I have a brain tumor which it is on the part of the brain that does the hormans. Sorry bout spelling. The only way I get my monthlys is by been on the pill if I'm not on the pill I don't get them. Last month when I got them I stopped taking the pill to see if I get them and Iv been having sex with my partner I'm ment to get them today and I haven't gotten them could I be pergant if I don't get them when not taking the pill can I fall pregnant but when I take the pill I get them just need some advice Plz