Irregular menstrual cycles are not Considered a reason for concern if you have just started having a period, and you are not sexually active. A real good resource is your own Mom or if you prefer your Grandmother or favorite Aunt. Friends at your age are most likely in the same boat as you are. Ever try Google for some information, or Teenager reliable web sites. Use common sense to get your facts together, not fiction. Be well and approach your personal health questions seriously and approach them with a level head and some good common sense. If you do not have the support at home to speak openly about your concerns, make an Appointment with your school's Guidance Counselor or Physical Education Teacher.
i wouldn't be real concerned, when you first start you can be pretty inconsistant for a while. i'd only be worried if you had pain,or some other unusual things related to your period. then you should tell your mom that you should see a doctor. but most of all don't worry,you'll be fine. good luck.