I had my gall bladder removed five weeks ago....?

and about two weeks ago developed severe pains in my chest on the left side and it can feel like some one has me in a vice. The pain eases if I sit reasonably still. The doctors don't seem too worried and think it could be just the way my body has reacted tothe removal. Had a blood test today and and ECG, having a exercise stress test next week. I am 51 with a family history of heart attacks. Has anyone else had this sort of pain after the operation? Am I worrying unncecessarily?