It's so exciting that you are moving on though

But I understand what you mean about being sad about it. Definitely get them a card and maybe send them scans of u/s and then take baby in too see them!!
Hopefully you have the same experience at your OBs office!! I know we got really attached to my OB and her nurse when we went through my pregnancy with Curtis. We brought him in to see them even before my 6 weeks post check up! hehe. It was sad when we had to say good bye cause we were moving, even though we knew we wanted to have more babies! James has said countless times that we should move back just to have our baby with them
I'm so thrilled for you though! Hopefully you get a nice OB and can feel that warmth there too!