Periods...

Chelsea • The name is Chelsea! I`m 16! I`m inlove with Tyler! He`s my baby.
So i have a very irregular period, and we went to the doctor and got some blood work done. The doctor said that everything was normal, but my period didn't come last month, I started the 7th. Usually I'm just a week late. I'm just not sure what it is. I'd like some advice or something. I know I'm not pregnant.