Go to the doctor. My husband had pain that was stabbing (felt like he worked out too much) and his neck hurt. It would come and go. He had what he thought was indigestion for years before this. Anyway, 3 weeks ago (at age 46) he had a heart attack. He now has 4 stents. I am sure it isn't that, but I would get it checked out, just in case.
Let us know what you find out and I hope you feel better soon.