First and for most lots and lots of hugs. Carcinoma is another term used for cancer. Mammographies are great for early detection, but can only go so far, and don't pick up everything, especially if you have implants or dense breast tissue. There is also a possibility that the tumors were not present before or too small to be picked up. At this time concentrate on get well and the right treatment.
If you feel strongly about this you can get copies of your last few years of mamos and get a 2nd opinion.