OB/GYN May not take me as a patient?

I got a BFP Sunday so I, of course, called this morning (Monday) to set up an appointment. I have to go to a high risk, maternal fetal medicine due to a few health issues. I went to see her in October for a preconception appointment and she said once we get pregnant just give her office a call and they'll schedule me. When I called, the scheduler said they'd have to have their nurse call me to schedule and she'd call this afternoon. I called around 4:30 because I hadn't heard anything and they said the nurse has to review my case to even see if they'll take me as a patient now and won't have an answer until Thursday?! Has anyone heard of such a thing? I am so nervous they'll tell me they can't take me. This doctor is the ONLY MFM that specializes in my health issues within 100 miles.