What s wrong with my rib?

For a couple of days one of my right ribs (right underneath my breast) has been very painful. I feel a very sharp pain when I inhale deeply and also sometimes when I run (I haven t been running much to test it out) It s very sensitive to touch but there doesn t appear to be any bruising or swelling. And it doesn t hurt around it just right on it. When I turn a certain way be it during the night or getting up from a chair during the day I feel an extremely sharp pain. I cannot laugh or cough, any movement like that (sneezing, burping, hiccuping) causes an extremely sharp pain. Almost like someone is twisting a sharp knife in my rib.

I don t recall getting hit or anything, I noticed it the day after a conditioning session for soccer. Its only been going on for two or three days now. My parents know about it but don t think I should go to the doctor.

Should there be a point where if its been hurting for a certain amount of time without getting any better that I should go to the doctor? Does anybody have an idea of what might be wrong so I could just kind of "milk it at home"? Also do you think I should miss soccer? I mean, if I can t breathe I feel like going to soccer conditioning would be kind of stupid... lol...

(I m 15 by the way)

Thanks for you help!