Im 15 years old and started my period 6 months ago but have not had another one since I know its normal to be irregular at first but is it normal to be THIS irregular? I'm not sexually active so I know I'm not pregnant please help me. What could be the reason for this I'm worried, if you have any information at all can you reply to this thank you.:D

Yes Ali, this is normal for some girls, especially if you are small (skinny and don't weigh a lot) as well as girls who are athletic.