Is it normal after sex and 2 months later you get your period?

okay, when me and my boyfriend first had sex (he was the vergin, but i wasnt) it was waaaayyy different than it was with any other guy i slept with. and after, i had some beeding but not my period, and about 2 months later i finally got my period and since than, it hasn't been the same at all(it wasnt heavy but it wasnt light either). When i slept with whoever else i slept with my period always went back to normal, but now it's messed up. It's way lighter than normal, my boobs get bigger and i puke whenever i eat/drink something. I'm just confused becos i don't really know if that's normal; well, i know the puking is belimic. although i'm still confused about my period.