Period or?

So I started spotting yesterday, today I only went through one pad, oh and my period was suppose to start a week ago, and now I'm spotting again. I've been having really bad cramps I'm going in for an ultrasound to look around to see what's going on because I was having the cramping for over a week, even way before my period  was suppose to come. I'm on the patch and I took it off last Saturday so I did. Any ideas what it could be if it's not my period? I'm not really sure if it is or not might I also add that the bleeding only lasted for about 2-3 hours then went back to spotting. I also normally have this weird pulling pain in my vagina I only had that for 3 hours too maybe at the most then it went away when the bleeding went back to spotting.