tell your mom that you need some pads.. or be like "i think i got my period..." i know its awkward at first, but serioucly. grown women, and chicks my age (15) talk about periods all the time. it becomes unawkard.. haha. just part of life(; and youll need to be reminding her for the next couple years till your out for girl stuff... soo yea. goodluck kiddo [:
You should check out www.beinggirl.com they have tons of useful tips and advice for girls who are wondering the same things are you:) I would really recommend looking at it! It is fun and colorful and they have all the answers to every question!