I think this is highly variable. The pattern I've seen so far is this: My kids would sleep through -- nine to 11 hours without a peep -- and then nurse a little bit and go back to sleep for a couple more hours -- from somewhere in the newborn phase, and then would suddenly start waking three or four times a night at five months old. (My youngest just started doing this, so I don't know how long it's going to last.) The older two continued to wake up somewhere between one and five times a night until around two years old, when they both, seemingly spontaneously, stopped nursing to sleep, stopped all routine nightwaking, and began sleeping like a grownup, only for much longer.
I hope it gets better for you soon!