Stomach pains.. gas or pregnancy?

okay so this is my story! 2 nights ago i had a late night snack of some artichoke hearts (italian ones, breadcrumbs, vinegrette, whatever else) the next morning i woke up with a crazy stomach ache which included sharp pains every so often, today i still had it but not nearly as bad. its in my upper abdomen sorta on my sides, or up and down the middle. dont really know what it is or if its a sign of pregnancy but i dont have any other early symptoms of pregnancy, plus the beginning of this month i got my period and the last time i had sex was new years (when i had a scare and took plan b so i believe im good) - what could this be? sporadic sharp pains in upper abdomen?