I havent started my period yet...?

7 stone isn't underweight for a 13yr old. U shunt b thinking about your weight so young, enjoy urself! I was worried when I was at school as all my mates started their periods before me, got their boobs n hips etc. I started in yr 11! I was 16 and I'v gone on to have 2 perfectly healthy babies. Trust me, you wish your periods to start, then you curse them every month! Enjoy being a child for as long as you can! :)