Rupture of membranes, any one had it done by their doctor?

I'm 40 weeks pregnant and my dr just ruptured my membranes, what should I expect? Isn't this when the water breaks? I'm back home waiting for contractions to kick in (hopefully soon) but I'm just nervous and want to hear about other peoples' experience with this. I'm already 2 cm dilated. I hope all goes well with me and the baby. thanks for your answers.