Help! (Long-ish)

So me and my boyfriend have been having sex for at least six months now. We usually don't use a condom, but I am on the shot, and I don't let him come in me. I just got my second dose of the shot about a week and a half ago, and before that we had sex w/o a condom. Before I got the second dose I had also been on my period for about three and a half weeks. After I got the second dose my period stopped, thankfully. A few days later me and my boyfriend had super hardcore sex, and I bled. We thought it was because of the sex. After that, we started using Durex condoms, which btw break way too easy, and I still bled. Then I would randomly bleed even when we didn't have sex. Not a lot though. And today we had sex and I bled and it burned down there. We started off using a condom but of course the damn thing broke. Please help.