Hi
Welcome to the MedHelp forum!
The first thing to be ruled out is angina by a 12 lead EKG. It can also be a mitral valve prolapse or a high BP. Costochondritis and gastric reflux are the other possibilities.
Since I cannot examine you and know other related conditions you may be having, nor is a detailed history possible on net, I have listed the various possibilities that should be looked into. Please consult your PCP for primary examination followed by proper referral.
Take care!
I would be seeing a doctor if I was you. As a matter of fact, a gentleman just told me of a friend of his, who kept ignoring some pain in his left shoulder that he was having, then one morning he was driving to work and he died. I'ts best not to ignore pain. It's an indicator that something is wrong. I'm not a doctor but would definitely urge you to be checked out very soon. It is possible that there is a very simple reason that you're having pain, but it's best to be sure. You only get one time around, take care of yourself.