You should expect for everything to go completely opposite of what you expect. Lol, that's just how pregnancy is. I had a friend who her first baby was overdue, and the second her water broke at 28 weeks because she went into preterm labor and didn't feel contractions.
it's different for everyone... for me I was in the bed both times.. my first I was asleep abd heard a pop/snap from the inside and moved a little and it came pouring out .. the second time I was going to sleep and felt/heard a snap and moved them got up walked to the bathroom and it started tricking down my leg abd it started coming more and more