Im 19 years old and female. I have always been active i have been working out just about everyday since I was 14 and even before that I was always out running around as a kid. My problem is that for a couple of days now the left side of chest/breast area has a nagging pain that will go into my armpit and whenever I run or workout it seems to be worse or sharper of a pain. At first I figured it was just gas pain or a pulled muscle, but as time goes on and the pain continues I'm very scared that I may have something more serious like an enlarged heart...any possible answers would be much appreciated