Is this at adjectives average?!?!?

I have have my period since June 2007 and the first time i get it till the next time i be late ever since it have been really precipitate like i draw from it every 2 weeks and 2 days thats only if im lucky sometimes its just 2 weeks. I know the first few years it can be irregular but this is getting to be to much. I am very athletic. I am a dancer who dance basically everyday. That might enjoy something to do with it but i lately want to know what to do. I told my mom once i relized but that was awhile ago. So what could i do and any direction?? I'm a dancer too. that happens to my friends. i ponder its cause our skinniness and athletics's.
There's many explanations for irregular period.
Some may be:
1. Frequent large amounts of stress, or spontaneous small amounts as okay.
2. Health; from as small as a cold to as big as a disease or STD. Change in diet will also effect it.
3. Activity; if you're suddenly remarkably active (whether it be within sports or just exercise) it will parallel on your period. Sexual amusement counts as well.
4. It depends on how far you are into your time of year. During the first few years, your period will be particularly irregular, but eventually it will steady out.
Stress relievers (pills), less physical distraction, more experience with menstruation, and diagnosis for your syndrome will help your spell return to normal.