My 2013 mammogram result: some calcifications no changes from 2012. Dr said is good since no chng but I'm worried. Wat r calcifications?

Calcifications. Are tiny calcium deposits in the breast. There are multiple causes, most of them benign. Most of the calcifications that show up on mammography are of no concern. Some will require follow up or biopsy. Based on their size, shape, and distribution, the radiologist will be able to determine how the calcifications should be handled.
Calcium deposits. There are calcium depoists in breast tissue that could be benign or malignant and they look quite different. If the report said benign finding then it's not a worrisome finding.