Microcalcification biopsy

I was wondering if anyone here has experience with microcalcifications?

In particular, whether they've been biopsied and if so, how many times? 

And have you had an MRI or other imaging to help understand the microcalcifications?

I'm curious because I had microcalcifications show up in my other breast from my first mammogram a year ago. Two core biopsies were taken but a clip/marker wasn't inserted. The diagnosis was: benign proliferative changes.

I've now had my second mammogram and they want to do another biopsy and insert a clip. They haven't said if anything has actually changed in that part of my breast in the past year. 

My surgeon is going to ask the imaging place for more information so I understand what's going on. 

I'm surprised that they want another biopsy so soon and seemingly without any change. I don't know if that's normal and whether that will be the case for the years to come?!