Had breast microcalcifications biopsied last year-benign. what if mammo shows new calcs? will i have to do another biopsy every time new ones show up?

Depends on the risk: Many calcifications detected by mammo are benign and require no further evaluation. Some patterns of microcalcification are more suspecious for cancer than others, thus require a biopsy for diagnosis. Usually, when microcalfications are detected, radiologist will attempt to stratify their level of suspecion to improve predictive value of biopsy by certain criteria or using other imagings.