You probably are not having a heart attack at your age It could be an abnormal rythym which can be normal in some people that you feel the flicking . Pain radiates for several reasons, ensure you dont have a mouth/tooth/gum infection or you could be grinding your teeth at night as well. Heartburn is another possibility, try a TUMS and see if it relieves the discomfort You certainly could be having anxiety or panic attacks; many people have similar feelings during an attack Even if they think you are overreacting (perhaps you say this b/c you have a history of doing so) if you have dull pain, sharp or radiating pain, especially down left arm, the feeling of suffocation, like an elephant sitting on your chest or nausea, vomitting, dizziness, sweating, you need to tell your parents or seek medical assistance. Take care and good luck