Bleeding. Help please.

I'm 31 weeks pregnant. My fiance and I had sex earlier today around noon. Then we went out on a lunch date and when I got home and peed I saw blood. My MIL told me that bc I already lost my plug that it's just my cervix bleeding. Well a couple hours later I got up to pee again and I'm still bleeding. I don't think it was because of the sex because it was atleast 7 hours before I saw any blood but I could be wrong. I'm not having any cramps or contractions and the blood isn't pouring out of me or anything. It's just there when I wipe. And I've decided that if I'm still bleeding tomorrow morning then I'm gonna go in. But I was wondering if its normal or if anyone else had this and can tell me what's going on.