I read somewhere that if a woman gets her period before 12 years of age she is higher risk for endometrial and breast cancer. is this true ? i got mine at 11 and half years of age?

While early onset of menstrual periods have some association with eventual development of breast cancer, I believe that association with uterine and ovarian cancer has been quite inconsistent. Also I believe that late onset of periods doesn't necessarily protect you from developing these cancers. Don't obsess about cancer. Just get your regular checkups during the years.