Without knowing your complete medical history i doubt anyone can really answer that question but the bottom line is the bottom line...if the doc feels it isn;t heart related after examining you the chances are its not. There are super specific symtoms with heart related issues and really nothing that you have posted or leading in that direction. Sometimes people when they are worried don't breathe properly and get air pockets in their bodies or plebs as they are known.....that is my best guess here......if you have had no one in your family have had a heart attack at age 50 or younger you aren't even in the higher risk group.....you may simply as i am sure your doc has told you stay away from any food groups that cause you to get gassy....i am sure that the reason that you don't feel anything while at work is because you are distracted by your work and not concentrating on the issue....which is also a sign it is not your heart.....i tend to agree with what your doc said...if you got a clean bill of health on your heart i wouldn't look for trouble where there is none and count your blessings it isn't your heart.....
Chest pain that is prolonged over a long period of time, many months or years, is very rarely heart related. It sounds like your heart has been checked out very well, I wouldn't think you have much to worry about. It actually sounds more anxiety related. The mind can cause many issues. You feel that first twinge and your anxiety takes over making more symptoms start and the pain worse. Unless you take something for the anxiety, other meds won't help as there may not be anything physically wrong.
Here's the key, when you have these pains make sure you look for other symptoms of cardiac distress like shortness of breath, sweating, back pain, pain in the left arm and shoulder. Chest pain from your heart normally is a constant pain and lasts 15 mins or more, gradually building in intensity. Also, what were you doing when the pain started? Chest pain from CAD almost always presents with exertion, pain that comes on at rest is very rarely related to your heart. You may want to request a Nuclear Stress Test for some reassurance, but remember, the more tests the more opportunity for a false positive which could lead to more invasive and dangerous tests so you need to be careful not to over do it, but I think a stress test would be a reasonable request.
If you have chest pain with any of these other symptoms please get to the ER to be checked out.You should ask your doctor about something for anxiety if you do not already have a script.
I hope this helps,
Jon