I've had similar pain. I also went to the ER with it and arrhythmia (PVC's). The ER doctors didn't find anything seriously wrong.
My best friend is an Echo/Respiratory Tech who does ultasounds of the heart. She said that heart pain is more of an ache, so if you feel a sharp pain it is most likely due to something else. I keep that in mind whenever I have my various and sundry chest pains.
Dull/cramping ache=possible heart issue
Sharp pain=something else
It helps me get through the fear. I hope it helps you, too.