Is anyone else's ultrasounds through MFM instead of their normal OB/GYN?

Hi there. This is my second pregnancy. My first was in 2018 in a different state and I always saw my assigned OB/GYN for all ultrasounds and care except for the 20 week anatomy scan, which was done at a MFM office. This time around, I'm seeing an OB/GYN who is in the same office as MFM and MFM is doing all of the ultrasounds, though I'm not deemed high risk at the moment. I just got ultrasound results back yesterday and the physician who cleared them was the MFM doctor, who is now listed as part of my "care team" though I never saw him or never got a referral to him through my PCM, which is required for my insurance.

I'm not sure what to think here. Is it normal for MFM to do ultrasounds, but appointments be through the low-risk OB/GYN? If anyone has been through something similar, how did it go with insurance? My last birth was 100% covered with zero co-pays, as it should be, and I'm afraid that the use of MFM for ultrasounds is going to mess up my coverage. Thanks.