Has anyone suddenly started having very short periods? I started having irregular periods about a year ago but was on the pill. I was advised to come off it to get my body back into sync and did so last summer. My periods became regular fairly quickly. However, despite their regularity for the last few months they have lasted as little as a few hours, even though I am still having terrible PMT, stomach ache etc as normal. They used to last about 3 - 5 days. There is absolutely no way that I can be pregnant. Has anyone else had this?