Do you know how to check for this?

A proper breast self- examination (done at least once a month) goes like this. You should be lying on your back with your arms above your head so your breast tissue is evenly spread out. Knead the breast in small circles, starting at the nipple and working outwards towards (and including) the underarm area. But research showed that while self-examination raises awareness among women, by itself it does not cut the mortality rate from breast cancer. So make sure you are examined by a trained health professional on a regular basis. If you do feel a lump and your doctor says the mammogram shows nothing, you ask for a sonogram. In younger women, breast tissue is denser and mammograms may not show as much as they do in post- menopausal women.