Bleeding after sex, x6 days now

I have never bled after sex. We didn’t use protection, and everything stayed inside me(if that makes sense). I am on birth control. We had sex Friday and Saturday, I was ovulating also. Sunday I started bleeding light pink blood and all week I have been cramping and bleeding red blood off and on. Help! I don’t know what’s going on. My period is supposed to start in 5 days. It’s always on time and never spotting through the month. Can anyone help?