THanks for the query
Hardening of the muscle is nothing put calcification and it is quite common. The lump from a calcification is very different from the breast cancer
which tends to a be little more softer and less smooth than a calcification, with clinical experience u can easily differentiate the two
Since u have no breast cancer family history, u r less likely to have it.
I am happy u r taking care of yourself. Keep it up
Have a healthy life