Some Dr's will do the referal to the hospital you wish to have the baby in and then the hospital will send out the time and date of your book in appt which can be around 10-12wks. Then you should get the forms to book your 12wks scan in and you just take it from there.
Also you can do shared care or just hospital care.
Shared care you go between your Dr and the m/w at the hospital and hospital care you have all your appt's with them.