I'm 26,160 pounds, no medicial history. I get periods maybe twice a year that lasts afew days. I had sex for the first time 4 weeks ago. A condom was used, but me being a stress ball, took plan be less then 12 hrs after. Ever since then my stomach has been feeling weird (alittle hard, I'm not in pain, its just a weird feeling). Could plan b did something to my stomach,could I be pregent,could something have happened,cause of my first time having sex?