Should I call labor and delivery?!

My doctor never answers me calls so that is not an option. I know bleeding after sex is normal but I am concerned. 35 weeks pregnant and me and SO just had sex. Nothing too rough or anything but I am seriously bleeding. Like bright red. A period bleeding. I put a pad on and I am bleeding on the pad. The sex was twenty minutes ago and I'm still bleeding. I wish my doctor was more reliable but I don't know who to talk to.