How To Increase Breast Size?

Hi,

I'm a thirteen going on fourteen year old girl and I am nearly completely flat chested. I haven't had my period and my nipples have been puffy since summer 2009. I've had discharge in my underwear but I wear a 28 AA sized bra. I seem to be the only girl in my class without boobs. I swim a lot in summer and my mum said that she suffered from the same problem at my age. I weigh 36 kilos an am about 1.50 metres tall. Your probably going to say: don't worry its genetic but is there anyway i can increase my breast size?

thanks for your time