No period for a while now, then this happens...

I havent had a period since my girls turned 6 months. They are now 14 months. So i havent had a period in 8 months. I havent been feeling well. Sore breasts, sick, i have been getting a lot of cramps. I go in the bathroom today and there is blood on my underwear. This happened to me while i was pregnant with my girls. At about 14 weeks. I found out i was pregnant at 10 weeks. What could this mean? Am i just going to start my period or am i pregnant? We arent trying to get pregnant. My husband uses condoms. We hardly even have sex. Any ideas what it could be..