I Am 13. I Am Suffering From Chest Pain

Okay so i m a 13 year old boy. Lately i ve been getting some pains around my chest and i think my heart . Sometimes it lasts like 10 seconds and it feels like.... i can t really say but usually i might bend over or clutch my chest. Other times it s just for a sec and doesn t really hurt. What is it? Is it serious? My mom said she was gonna take me to a heart doctor if it happened again so i ve been lying and saying it hasn t. I don t think it s serious but i don t really know _ ; It could be just heart burn or something cause i don t know what it feels like. If it helps anything i m pretty active. I run for 30 minutes, do 500 crunches a day, 100+ pushups. Is it that i m excerscing too much? I m not afraid to go to the doctor, i just don t really wanna waste the 50 bucks if it s just nothing.