Sharp pain in shoulder blade and chest??

[optimistic1]

Tonight I got a sudden sharp stabbing pain in my right shoulder blade and it went to my chest and took my breath away. It lasted about 30sec to a min I went back to feeding my daughter. Awhile later I got back up and it came back again going to my chest and alternating from my shoulder blade and back to my chest again taking my breath away. Its gone now and hasn't come back. I'm kind of worried but I have a tendency of ignoring things thinking if it were something to worry about it would get worse..I'm only 21 what could it possibly be? Something serious or just a pinched nerve?