I'm not sure about the other states, but in SA, there is a pregnancy helpline that you call and from memory, I think they book you in for the first appointment or give you a booking number to give to the hospital they send you to.

Although this is a new thing - with DD, the dr who confirmed it gave me a referral letter and I think I called the hospital myself. It might be worth you calling the hospital yourself to see what their procedure is. And I suppose it also depends on what mode of care you go for.