New lump over the breast

Hi guys. I had two previous lumps one in each breast, both were fibroadenoma and both removed a few years back.
Found a new lump couple of month back, over the left breast so GP referred me back to the clinic.
Last week they did mammogram and ultrasound guided core biopsys X 3. It's about 1.5 cm and actually attached to the muscle between the collar bone and Brest. Results will take a week and obviously I'm a bit freaking out, was not painful not moving either unless muscle moves.
Anybody have any idea having it attached to the muscle is less or more chances for malignancy?