Early signs of pregnancy or reasons for concerns?

Okay so.. I've had my period since last Sunday.. So for about 12 days. Before my period came my boyfriend and I had sex once. During that I felt a little.. Sensitive I guess ? Sorry to get a little descriptive here but he couldn't go too deep because it would hurt when he would try to push himself in all the way. At first I didn't realize the pain, but after a while it was really starting to hurt and then when I asked him to take a break I started having pelvic pain and stomach pain, almost like period cramps but a lot worse. I kinda just figured it had to do with my period coming and thought nothing more. So idk if this is related to the problem I'm having now. My period came early ( which isn't abnormal cause my period never has a set date. It either comes late or early. Never on time 🙄 ) and it started out normal, heavy flow and getting less as I reached five days. And then it was just that brown looking blood that's just supposed to be left over blood or whatever right ? But then.. I'm bleeding brown blood up until the day before yesterday and yesterday night I noticed my flow getting heavy again and I'm having cramps and back pain as if I'm starting my period all over! So any ideas ?