I have had my period for about five years and it has been like clockwork for the past three. It is 27-28 days apart and lasts 3-4 days, with only a medium amount of bleeding, and very mild cramps. However, for the past 5-6 months, it has been extremely irregular. It was three weeks late one time, two weeks early another, and varies in between. It has also been longer, between 8 and 9 days. It is accompanied by heavy bleeding and cramps so bad that they have caused me to vomit on occasion. I cannot see the doctor until late January/ early February, so I was wondering what you think may be the cause of this.