What Causes Itchiness And Pimple In Breasts After Undergoing A Mammogram?

i had a mammogram and breast ultrasound last week...since then i had an itch on my breast and today i see like a pimple pop on the aerola of one of my breasts...is that normal...is it possible i had an allergic reaction to stuff they used for ultrasound as i didnt go home right away to shower and get rid of the stuff..the technician was rude and rushed me so i coukdnt even clean the gunk off