with my first son I was in early labor having contractions that were 15 minutes apart and the hospital sent me home saying it wasn't broken yet. It finally did break about 10 hours after early labor started so i headed to the hospital and I was 7 cm dialated. My 2nd child i was induced and fully dialated so the doctor broke my water.
I was induced so I had pitocin induced contractions going on. They were going to break my water & right before they told me to get a shower... that's when mine ended up breaking on it's own. But my contractions were steady prior.... due to those drugs! lol
I had contractions for 6 hours (2-5mins apart the entire time) before I went into the hospital as soon as I got there they broke mine, but i'm sure if I waited even another hour it would have broke on its own.