I've been having problems with irregular periods, normally they're like clockwork. On the 26/6 my period was about 10 days late and shorter than normal. My last period was on time but lasted around 6 hours, stopped for two days and then a day later I noticed slight spotting. Two days after that I also noticed I was bleeding after sex. My periods normally last about 3-4 days and I have never had any problems, what could be the problem now?