Hi, when you first start your periods they can be very irregular .
My daughter started hers at !2 years old and they were happening every 2 - 3 weeks and were very heavy. After no improvement she has finally started to take the pill but this was after 6-7 months and on doctors reccomendation.
Usually they will settle down themselves but please make sure you get your Parent to take you to see a doctor if they are no better soonn.
I would be ready to call the doc on day 9, myself. And in the meantime, take an iron supplement daily.
when you first get your period it can take up to 2 years before it becomes regular, and it's possible to have your period for 10 days or longer. usually if you still have it at the 2 week mark you should call your doctor but having it for 8 days isn't that uncommon