Hi so the Sunday before thanksgiving I had unprotected sex and the next night I took plan b. I have always had irregular periods but I took it anyway. But ever since that day I have felt really weird. But now 12 days later, I still feel weird/different and I have cramps and light bleeding. I usually have really heavy periods and they are extremely painful. This started yesterday afternoon. Could this be implantation bleeding or side effect from pill. Or am I just being crazy? Cause I have read so much info the last few weeks and people are saying it doesn't work with overweight women. I need help, i have nobody to talk to about this.