Can I be pregnant even if I have my period, but my period is heavier than normal, ihave really bad cramps I don't normally have, I am experiencing nausea, mood swings, and I messed up on my birth control a few times this months?

Very doubtful of pregnancy, with prgnancy you have a light or no period, not a heavy one.

But with that said, birth control even when taken properly is not 100 percent effective.
Sounds like just a bad period this month

Thank you. I was trying to get clarity for my boy friend because he was freaking out and this will help a lot.