Your making yourself sick. Don't stress out while your waiting for your next period cause that will just delay it.. its a very low chance to get pregnant out of you ovulation days. Google it an it will tell you the days you ovulate.. even during ovulation its still hard to get pregnant. Before I met my husband.. Every single time I had sex . (With my EX it was always with a condom) I would freak myself out and end up making myself feel nauseous even tho deep down I knew I used protection I would think I was that 2% that got pregnant with a condom. Then my period would come.. Point of the story is your probably not pregnant.
Some women still have full periods while pregnant its rare but happens. Wait 3-4 weeks after the sex date and test yourself.