Advice..?

I need some advice, this maybe a silly question but last day of ovulation was 2 days ago, we had sex on 4 of those ovulation days, one of those being the highest fertility percentage. And for the past couple of days I've had really intense cramping in one side and my moods have been very up and down, one minute I'm happy and the next I'm sad or just want to be on my own.! Surely it can't be signs of pregnancy so soon?