I'm sixteen years old, and have minor asthma, and at times I get short on breath or my it feels as though my heart is beating very hard. Sometimes for no reason, and mostly at night. Anyways, last night I was sitting in bed, just watching some TV when I got this sharp, shooting pain in the left side of my chest that went down to my arm. It went as quickly as it came and ended up doing it another time. I'm really scared. What do you think this could be, because I've been freaking myself out about this all night and day.