Calcifications usually indicate proliferative changes in the breast, and fat necrosis is rather unlikely. Proliferative changes can range from hyperplasia, fibrocystic diseases, and malignancy in the extreme end of the spectrum.
However, there are patterns of calcifications that are indicative of malignancy, and I'm sure your doctor will tell you if this is the case. You can also ask your radiologist about the BIRADS score of your mammogram since this will tell you if the lesion is more likely benign, malignant, or would need further evaluation (http://biradsclass.blogspot.com).
Regards and God bless.