TriCare Prime

So I am currently 30 weeks pregnant and my sponsor for TriCare is my husband who is active duty (I’m a civilian) and for reasons I no longer would like to be seen on base and deliver on base. I have a civilian OBGYN all pick out who accepts Tri care prime. I even checked on the TriCare website to make sure I was able to see this obgyn. However when I called TriCare they told me that I must be seen on base and I can’t go anywhere else and I must deliver on base as well. Has anyone else heard of this? I have friends who are pregnant right now that are able to deliver off base and see a civilian obgyn. My primary care doctor before I got pregnant is even a civilian that I was able to pick out on my own. Why is this different that I can’t pick out my own Obgyn and deliver off base? I’m so confused.

I know when I got pregnant my primary care providers referral was to a military obgyn and military hospital, so is that why? Because of my referral she gave me was only for a military obgyn?

If so would I be able to go back to my primary care provider and ask her to change my referral to the civilian obgyn I was looking at?