Switching practices.

LJ • Baby girl born Feb 19, 2015 and second girl born Jan 20, 2017. Baby #3 due in October!
For my daughter, I was at a practice that had 6 or 7 doctors that I basically rotated through for my appointments. I ended up being induced and delivered with the one doctor I hadn't even met yet. For this pregnancy, I want to go with one doctor. I've made an appointment with the new doctor on the 14th and the old ones right now on the 16th. What should I say if I call to cancel with the original doctors?  I loved all of them and feel guilty about leaving, but for consistency, I just want one doctor.