should I be worried?

I am a 28 y/o In good health with a paternal family hx of breast cancer (aunt and great grandmother), my concern is for the last few days my right lateral breast has been tender and I can feel a lump under the lower lateral side of my nipple. The discomfort is mainly if I bump it and feels similar to what it did at times when I was breast feeding (which has now been three years ago). I am mid cycle, post ovulation. Could this just be part of my cycle or should I be concerned. Could a duct just be irritated? I am only an A cup if that makes any difference. I appreciate any input. Thank You.

[Cleveland Clinic]

Dear KeyD, Breast pain is a common breast symptom.  The reason for breast pain is not clearly understood, and is not usually associated with breast cancer.  Breast pain is sometimes associated with hormonal variations and is then called cyclical breast pain.  Noncyclical breast pain does not seem to be linked to hormonal variations and is often localized to one area of the breast tissue.  Noncyclical breast pain may or may not be the result of an injury to the breast.

A new breast lump is something that should be evaluated. It is impossible over the internet to evaluate a situation in total.