Stereotactic biopsy

i have IDC and was suppose to have surgery on the 28th. The day before, my surgeon called to cancel. There are suspicious microcalcifications that we want to test first. On the 29th I had an MRI and was suppose to have a stereotactic biopsy on the 10th. Today the nurse called to say they want to do it sooner. She will call me back tomorrow with a different date. Now I’m worried as to why they want to do it sooner. My surgery is on the 18th but not sure what is getting done now with this new tests. Should I be worried