Breast screening

Hello everyone this is my 1st time posting, I'm 38 I called my doctor last week to get help with my back aches and mentioned to him my nipple had gone inverted he called me in and when he checked me he found 2 lumps in my left breast he told me he would get me in for a mammogram within 2 weeks, I have had a letter come today saying they have booked me in for breast surgery on the 5th of January I'm a little confused is this normal ? I have tried calling the hospital and getting no joy, has anyone else had this ? I lost my Mom in June to cancer so I'm feeling anxious, thanks in advance