Had my first mammo and they found assymetrical density of right breast. Got a diagnostic mammo followed by ultrasound. The radiologist said "It's ok. See you next year" I know what you're going through. I spent 2 weeks agonizing and surfing the net. One thing about a diagnostic mammo and ultrasound, they tell you right then what they found.
I doubt your additional films is to see if the area has changed. These films will be concentrated on the suspicious area and involve some magnification. Often these areas will disappear on magnification or spot compression films. Whether it is an issue will be clarified when your next films are taken and read. There is no way to speculate at this point. Regards ....