Thread: When should she get next period?

My niece had her first period August 12th, 2010. She then got it on September 8th, 2010. She keeps asking me and her mom when she should get it this month. We keep telling her that it should be October 8th. She does not believe me and wanted me to ask for your opinions on here. Any help would be great.

Every 28-30 days. If she just got her period, she might not get it again for a while. When I first started, I got mine every 3-4 months. But yeah, if she's automatically regular then 28-30 days from the end date of her last period.