Why am i so you and get migraines?

well i am m 13 almost 14 and almost every day i wake up with a headache and usually have the headache all day and usually if i don't wake up with a headache i get on during the day at some point. i love riding bmx but depending on my headache it depends if im gana go home after school and ride or take a nap and im turley fe up with headaches because iv had them for about a year and a half and my doctors finally getting me a MRI and i would lke to know form you y are theses headaches running my life ??