The overwhelming majority of abnormal screening mammograms are caused by benign (harmless) processes.
The purpose of a spot compression mammogram is to focus on a particular region of the breast to achieve better imaging and helps clarify things..
Rest assured that a Diagnostic Mammogram is pretty accurate. If anything suspicious were detected ,more testing or even a biopsy would have certainly been recommended by the Radiologist.
Please take note that if cancer is present,when the area is compressed, the cancer tends to stand out as other tissues are moved away.
So be happy,you definitely have nothing to worry about.:)