Heart Question...

I've heard of the disease called Angina Pectoris, and for the past two years, I've been having sharp, random pains in the area around my heart, right above the chest.  In no way is it an everyday thing, and maybe happens once or twice a week, maybe three or four times a month.  It isn't regular, but it normally happens when I'm not doing anything.  If I'm playing a sport or running or walking for exercise, I'm just fine.  But if I'm sitting down and drawing, reading or something of the like, it'll happen out of the blue.  The pains last for only a moment or two, and if I breathe deeply (or try to, more like) the pain is excruciating and forces me to take shallow breaths.  This is really annoying when I have to yawn, because I have to wait for the pain to go away before I can.  I'm 16, and I weigh 195 pounds.  Is it possible that I may have Angina Pectoris or some other heart disease?  This condition worries me.