Can i be in danger of having breast cancer am 21 my aunt had breast cancer and my uncle died of cancer also my grandfather died of cancer ?

Depends: Any woman is at risk for breast cancer. The average woman has about a 12% risk of getting breast cancer in her lifetime. You may be at increased risk if your first degree relatives have had breast cancer, ovarian cancer, or prostate cancer, particularly at a young age. See your doctor, who can better assess your individual level of risk.