question: Hi I am a 32 year old woman 120 lbs, mother of two little girls, dedicated to excercise and healthy eating.  I run 3 to 4 miles a day, never feeling any discomfort, or shortness of breath during exercising, but this last few weeks, I feel slight discomfort in my chest off to the left and sometimes in the shoulders.  Went to the doctor (internal med.) he said he felt there was nothing wrong with me, maybe stress and anxiety.  So do you think I have something physically wrong with me or am I just too in tune with my body and am telling myself there is something wrong when there is not?