What could be wrong with me?

so for the past few days every time i eat, my stomaach will start hurting. its not excrutiating pain, but enough to make me quit eatin. like last night i had a medium blizzard from DQ, then my stomach hurt. this morning, a pop tart. i culdnt start on the second one cause my stomac started hurtin! plz help! any ideas of whats goin on?