Repeat csection question

[eggs#4]

So I'm having a repeat csection. And have it scheduled but doctor says if I go into labor to go into hospital and nurse will call him in. I never thought of asking him at what point will they do the csection? After you dilate to a certain #? Stage? I'm getting to the end and thinking about this a lot. And I won't see him again for three weeks at 36 and my first baby came that early! He is on vacation next week so I will see his PA instead. Any other moms been here and give a lil direction?
Thanks!