I just took my two month old son to the doctor yesterday for his checkup. She heard a heart murmur that she had not heard before and is sending us to a pediatric cardiologist . He has had poor weight gain in the past and we have switched his formulas to a higher calorie formula and he seems to be gaining fine now (although we are going to go see a GI doctor also). I am so worried that I am not sleeping or eating . What should I expect at the doctor and am I right to be concerned?