I'm 13 right now and i don't know when i will start having my period. A lot of people say that when i have my period, it will make my boobs bigger also. Is that true? I've been having these white stuff on my underwear for a long time now. My friend said that if you have the white stuff on your underwear, it means that you will have your period soon. Is that true? And does anyone know how long you have to have the white stuff for?