Aprx Timeline?
Since you've already been referred, why not go ahead and give them a call? I think they would have the best answers - all clinics seem to be different so if you already know where you going now would be a good time to call. Introduce yourself, make sure they got your referral and don't need anything else from you right now, and of course ask them your questions.
Because the bottom line answer to your question is that it's different for everybody=)