Here's the situation

I am 23 days late for my period. I skipped a month. Now this HAS happened before. Once before I was sexually active and once last year. I took two pregnancy tests and I am going to the doctors in a week. I originally thought maybe I have developed pcos. However me and a friend were talking and she said I wasn't hairy enough to have that. I had a miscarriage in July and I was also on the depo shot. Ever since either getting off the shot or the miscarriage I've been having irregular periods. My periods were also irregular when I wasn't sexually active at all. So ahe put me on the pill to regulate it and help with bad cramps. Anyways ever since I got off the shot which was August. My period has been irregular. Two months I had a two day period. The next month I had an eight day and then December was six days now I've skipped a month. I have no pregnancy symptoms unless I get stressed or freak myself out thinking I am pregnant. Then I get nauseas and feel my lower tummy for a bump. If I were pregnant though it would only be seven weeks, six weeks or five weeks. I don't think I could feel a bump that early since I am technically morbidly obese. I can't think of any other reasons why id skip a period. Can anyone else think of a reason?