I had sex for the first time the day I was supposed to get my period and I didn't get my period until three days after. It's been only three weeks since that day and I haven't had sex since that and my period was normal and everything. I'm might just be paranoid or something since my biggest fear is getting pregnant but recently I've been feeling nauseous in the morning and I've been feeling not myself. Is it possible that I could be pregnant even after getting my period?!?!