Extremely short menstrual cycles while on Micronor

I have been taking Micronor since Dec. 24, 2006. I have gotten a period every 13 days since Dec. 31. This is not spotting, which they mentioned could happen, this is actual bleeding and cramps. I am totally freaking out. It seems like the Pill isn't working. I am taking it because I am breastfeeding and I don't want my milk to dry up. But I REALLY don't want to get pregnant again so soon, and it seems like I must be ovulating. Has anyone else ever had this problem?

Incidentally, I am also losing weight and my hair is falling out a lot. Not sure if they are related or not.