Just to add,
My cervix was still posterior and had an anterior lip at 7 cms dilated.
Lachlan was born postrior and the cord was around his neck, so we did pretty well.
Things just moved very quickly but i do have a history of fast labours. my other ds was 40 minute labour.
I had gone to the hospital to be checked out as i was strep B positive, when i got there i had no contractions, bub and i were monitored for 2 hrs. I got up went to the loo and thats when it all started. It was very intense and i didnt get a break in between my contractions but the thought of bub coming kept me going.