I think it is a good idea that you are going to get a biopsy. I would want to be absolutely sure. Too many have been told to wait 6 months and then it turns out it was cancer and it has only gotten further along. I am not trying to worry you, 80% of lumps are benign and microcalcifications are usually nothing. Just getting it biopsied takes the "what if's" out away.
Please let us know how it goes. We care.