My issues REALLY started after I was diagnosed and was trying to get the surgery/reconstruction preferred. At that point, I did a bunch of research on-line about my surgery (DIEP), who does it, and their reviews. Breast Cancer.org was also a good resource.
You can also go backwards from a breast surgeon (start here:
https://www.breastsurgeons.org/). You can always find one associated with a medical group in your area and find out where their office recommends for Imaging.
When is your next mammorgaphy appt? You should definitely keep the appointment while researching things. Hopefully you won't need to go down this road.