When you are given a BIRADS score of 4 in your mammogram,it isVERY important to have a biopsy and find out the nature of these calcification.There are NO other tests available to know for sure what's going on.It's a good idea to be tested also for BRCA 1 and 2,to know if you are genetically compromised.The CA 15-3 test you had, is not sensitive or specific enough to be considered useful as a tool for cancer screening.All abnormalities in the breast,when found suspicious have to be biopsied..(No matter what other tests you had).We all went through biopsies and for sure we tend to be scared about something we don't know,but there is really nothing to be scared about.The skin will be numbed and the procedure will cause a little discomfort,but not real pain.After your biopsy and pathological report is in,you doctor will tell you what are the necessary procedures to follow.Please heed your doctor's advice, you'll have peace of mind...Nothing can be worse or scary than not knowing!.Wishing you good luck and a BENIGN finding.