Hi my name is Xavialune and I am 23 years old..I am pretty sure that I get heart palpitations from time to time, sometimes for no reason at all. I haven't been diagnosed but my brother has an irregular heart condition of some kind, though I can't remember what. It has me worried because yesterday while I was doing some particularly intense cycling (going up a steep hill which I am not used to), as I got to the top my jaw began to hurt. It felt like it was cramping up on both sides. Then today I saw it was a sign of a heart attack. I don't think I had one, but I don't know, I'm worried about my health. I just moved out to california and don't have a personal doctor yet. Can anyone help what this might be?