My period is about three weeks late, but I started a very light flow yesterday and it continued today. My flow has always been very heavy but this has been light but more than just spotting. I've been having cramps and bloating like my usual period, but it's all very late. I've never been late more than a few days before. I hsvent been having protected sex for a few months, but I've taken 2 pregnancy tests, both negative. I've been nauseous and had diarrhea the last few days.