Here's the thing, I have fairly irregular periods. A few months ago I was having normal 28 day cycles. Everything was like clock work. In October I was 9 days late for my period, thinking I was pregnant. But my period came and was my normal flow. Light the first day, HEAVY the next two days and light the next. Since then I've had anywhere from 30-33 day cycles. It confuses things. Anyway, my boyfriend and I had sex 3, 4 and 5 days before my "predicted" ovulation date. This month I was later than normal. I began bleeding on day 38 of my cycle. But this period was nothing like others. It was decently heavy the first day, then the second it was almost gone. Now today it's completely stopped. I haven't seen any blood clots. And when I wipe, there's no blood. I wore a tampon yesterday, while at work and I almost felt like there was no need for one. I don't know if this would be implantation bleeding or my period. I have tested, two days before my missed period and it came up negative. A side note, I've also been feeling so nauseated, backache, completely exhausted and lightheaded. Sometimes to the point where I have to grab a hold of something so I don't fall over. The only thing that has me convinced I'm not pregnant is that my boobs haven't seemed to hurt at all. So any ladies going through this, please, please, please reply!