Chest pain is always scary. While stomach issues is likely your problem, it can't hurt to go to your Dr for a quick EKG if the pain persists.
The first two times I had bouts of GERD (or whatever it is I suffer from...I'm not quite sure what I have...doctors are pretty useless sometimes) I swore I was having a heart attack because the pain is so similar...even radiating down my arm and up into my jaw. Even though I was burping up a storm (hence my screen name) I was still scared enough to go to the hospital....both times, feeling silly because it wound up being gas.
BUT better safe than sorry.