Ovulating or early implantation?

Soooo this is my first ovulation cycle that I've had in over a year because I've been on BC. I can't tell if I'm preggers already or if I'm ovulating. I have slight cramps, random hot flashes, I'm exhausted, if I get hungry it makes me nauseous. The calendar says I should be ovulating but we've had a lot of sex right after my period up until a couple days ago so i wouldn't be surprised if I was pregnant already but am I supposed to be able to feel pregnant already?