I had something similar Sharon.

I had a spot that showed up on mammogram, and I had multiple attempts to have the area biopsied but they all failed because "it" was so very deep against my chest wall, and very difficult to get to.

I ended up having the "lump" removed in a surgical operation and it turned out to be a benign area of calcification.

I hope that your's has a similar outcome, but I can certainly understand that you may be feeling a bit stressed by it all, because I was too..