I was 2 cm for a week before I even went into labor and when I finally went into labor I was in labor for 36 hours. It depends on if you are being induced or in natural labor. Every women is different so it's hard to tell.
My first 14 hrs labor my second 27 hrs labor my third .. 2 hrs labor !! All depends good luck
With my son I was dialated to a 2, three weeks before I was even induced. It all depends