Def. get your heart check my Mom has that same heart pounding, and tightness because of her age and that my father had a heart attack last year off to the Doctor Isent her, she has anxiety, a panic disorder related thing. It's not pleasant but better than a heart attack. And don't say you don't feel any stress around friends or other times, it doesn't have to be timed to the feeling at all, it can happen after stress or when you don't even feel that you are stressed but something is still lurking in the back of your mind.
I hope it is nothing serious.
