I was doing some heavy petting with my boyfriend the 12th of decemeber. I was scared about his precum and if it went near my vagina opening. Although I had clothing on I was just in my undies. I got my period two weeks ago and it was a regular one that was no way light and lasted a good 5-6 days. But today I started having pain near my navel and have been nauseous. My left breast isn't tender but i feel small pain near my areola and the other is fine. I'm on a contraceptive (Estrostep) but I haven't been totally devoted in taking it. Am I pregnant or am I paranoid?