Go see a doctor... When doctor says no problem, ask doctor to
recommend you to a specialist... When specialist thinks no problem,
suggest to do more test and check ups...
Like what bear has mentioned, many illness do have common
symptoms... In a normal clinic, doctors can only diagnose you based
on clinical symptoms... Some things might just be missing out? A
common mentality is that when it comes to cardiac problem, young
people usually would have a less likelihood of a serious problem..
The worst would be that it'll really starts to bother you when
you're at a much older age?
From what you and wuming have described, it could be some valve
prolapse... Can be quite a common thing nowadays... And yes, it'll
cause SHARP pains on and off usually... As long as it's not really
giving you any breathing difficulty should be ok... For young
patients, doctors usually don't recommend taking of medications nor
surgery 
also... Cause it's
usually not justified to its needs...
