What are the Pains in my chest my heart?

I had pains in my chest for around maybe 3 minutes.It would hurt every 15 secs and it only did it once.Now the pain has stopped and now the middle above my left breast hurts what does that mean?Im really scared because my aunt died of a heart failure 2 years ago.Also i am thriteen.Im sitting here crying because im really scared.I took tums and I dont know what to do.I told my mom and she told me to sit down beside her and tell her when it started to hurt again but it didnt.Maybe it was the pose i was in i had my computer on the edge of the bed with me outside of my bed on my knees.Crunched over.Could that be it?I didnt have enough air to go through?Sorry its so long.God Bless