i have a sharp pain in middle of my back sometimes when i cough which causes me to hunch to ease it. the pain was right in the middle of my chest between my breasts. I have been doing alot of belching today which i dont normally do, it seems to releave when i let that air out. when i cough or sneeze i hold my chest so it dont hurt. when i took a nap today i slept on my stomach and when i woke there was alot of pain in my back. what can you tell me.