Getting the heart checked out is always a good idea when there's chest pain, even if you don't think the heart is the cause. But maybe your first doc already did everything that was needed.
Next place to go is to the local friendly gastroenterologist. Find out if you are having reflux or a galbladder problem. I have a hiatal hernia that is giving me chest pain exactly where it hurt when I had a heart attack a few years ago, so it can be quite confusing for us poor patients.
Do you have any other symptoms than just chest pain? Do you get rapid heartbeat, feel lightheaded? I have intolerance to several foods that triggers reflux, then tachycardia and chest pain. Keeping a food log helped me figure it out.