Sporadic Chest Pain

I'm a 22 year old male in pretty good shape, and have had random chest pains on my left side for years now.  They will occur perhaps once or twice a day for a week or so, and then not come back for a month or even more.  These chest pains occur only while I breathe deeply, and last anywhere from 30 seconds to 10 minutes.  It is a sharp pain that only occurs on my left side.  What could this be?

[stutterheart]

I really doubt this is anything related to a serious heart problem but you should see a doctor just to make sure. Chest pain can be heart related, either from something 'stuck' in the arteries or from a part of the tissue dying, or from all sorts of skeletal muscle, connective tissue or other stuff in your chest. I started worrying about these exact type of pains right about when I was your age. I was in really good shape and it freaked me out. I now have an arrhythmia but it is totally unrelated to the chest pains I felt and still feel sometimes.
So i think the chances of you having significant coronary artery disease or a cardiopulmanary embolus is infinitely small (unless you use hard core drugs). It's probably just that stuff holding your lungs to the side of your ribs or your skeletal muscles. Perhaps its just something a bit off with the nerve in there. The body is a pretty big mystery even today and there's no telling where many pains really come from. The best the doc can say is that it's not dangerous.
But that's for him to decide. Get it checked. If nothing else, s/he can screen you for cardiac risk factors such as enlarged heart, long  qt syndrom (syndrome) and WPW.