Blood?

I was just in the shower and I could swear I saw a little blood on my hand from my vagina. I'm 12 weeks pregnant. Slight cramping but nothing alarming. I checked with toilet paper and didn't see anything on that. I can call my doctors on call number but I feel terrible bothering him this late of it's nothing. Should I call him? Or just go to the emergency room? I don't remember bleeding with first pregnancy.