Pregnancy or BC side effects? Sharp pain in uterus, etc

I had a pregnancy scare in March (he didn't ejaculate in me but he did pre-*** without a condom), but thought I wasn't pregnant because I started my period. My periods in March-May all came one week early, and they were about the same type of bleeding except I didn't have as much clumps in the blood..like you know from the uterine lining...

I started birth control in the end of May and I'm supposed to get a period at the end of each pack (28 days). I'm on my third pack now and haven't had a period yet. About a week ago I spotted a couple times, once after sex once just randomly. I thought that's the birth control, even though I thought it was weird I'm just NOW getting spotting instead of when I had the same amount of rough sex for the first two packs (sorry if this is TMI).

Also around the same week I've been getting dizzy, I got a random hot flash at the mall in the dressing room, and my nipples have been very sore for a week, and they're rarely sore and if they are it's when I'm about to start my period, but I'm not scheduled to start until 2 more weeks.

I just ignored all those because I figured they were from the BC. But, yesterday when I was having rough sex, it was kinda uncomfortable. When we finished, there was a very sharp pain in my uterus I have NEVER felt before. I thought maybe stretching would help but it hurt even more! My mate isn't that big, he's normal, so I don't think he would have done the damage...

The pain faded but it still hurt a bit and still does. I also gained 4 lbs in 6 days and I wasn't over eating...The weight gain and all the symptoms have all happend in a a week to a week and a half.

We use condoms all the time (except the scare) and he pulls out everytime before he ejaculates. So idk if these are the birth control symptoms just now hitting...if a condom had a hole and pre-*** escaped..or if this is from the scare the first time..