Bleeding after sex

I am currently 15w2d with twins and I recently had sex with my fiancé. (We hadn't had it in a while due to my fear of miscarrying ) I had been completely fine through out the pregnancy already, doc even told me that the babies were on track and healthy, so we gave it a shot. I started to feel uncomfortable and felt like I needed to pee during it so we stopped and didn't continue. Hours went by and no bleeding during that time, till I started to watch a movie and felt like I was going to pee again, so I quickly went to the restroom. When I wiped there was bright red blood. I am not sure if this is normal, I'm trying so hard to not freak out. Any advice????