Irregular heavy bleeding and then PMS.

I regularly have my menstrual cycle of thirty two to thirty four days. On twenty third May, I took unwanted 72 but I got my periods on scheduled day 7th June, although the periods were very painful and it continued for 6-7 days starting stopping. My next periods were due on 10th July, but on thirteenth july, I got bleeding which was very very much painful and very heavy that I had to use 2 pads in 1½ hr. I stopped after 5 hours but again happened in night and again on 14th Morning. I thought that it was periods because I have normal periods of three days. But today (18/07) from morning I feel like PMS. I was sexually active on 9th July. Am I pregnant? Why could be all this mess and why could be that heavy bleeding? Is it really PMS or something else? Was that bleeding not periods?