Sounds like the dr just wasn't being very articulate. You may have a low risk of breast cancer based on personal and family history, but he probably meant that the microcalcifications are an indicator that needs to be checked out, rather than an increased risk. many women have biopsies done based on the evidence of finding microcalcifications, and many of these women have benign findings. But it is good to have it checked out, anyway.
Keep busy while waiting for a biopsy date, and then waiting for that date to arrive and the biopsy report after that. Turn your nervous energy into a good opportunity to get things done around the house, get some exercise, etc. And make sure to do some fun things, too - that will help you to relax.
Hope everything turns out ok.
Tre