J.L.
Sorry...I somehow missed this until now...
A lot of times it is the technician's error, or the equipment's inconsistency that causes a 'call back'
My mom had this done when they did not get a smooth picture of the side of the breast tissue that they PULL from around under your armpit (FUN!) and there was a shadow on the film.
I am glad that you got an appointment soon.
Keep posting, and we will keep you calm.:)
S.C.