Obgyn practice keeps cancelling and rescheduling my appointment

I am now 22 weeks and have had 5 appointments in this particular practice. (This is in USA). For every appointment they call a week before and cancel/reschedule the appointment which is so annoying. I chose that practice due to a doctor and everytime my appointment with her gets cancelled and they put me in with some nurse practitioner. I agree that its covid time. But its so frustrating that they are so disorganized and have to do this every single time.

Just venting out my frustration.

Should I change the practice that I go to? Is it okay to change so late into pregnancy.

Update: I should add that its a large practice with 10 doctors who do deliveries on rotation. The on call doctor does it. So I dont see that someones delivery is the reason for the rescheduling. The reasons they gave so far: 1. Doctor is sick 2. They need to maintain social distancing between patients 3. Doctor has an personal emergency 4. Doctor has to go for surgery. For every single appointment they have a new reason.