Switching Hospital(obgyn)... Help?

Im recently 20weeks I've only gotten 1 ultrasound to find out how far along I was, & that was at 7weeks. My bf is trying to get me into his Kieser Plan with his family... But the clinic I was going to send me to a obgyn that will deliver my baby once it's born. How can I make the switch please help or any information I should know about? I will like to find out what I'm having :)