Some women can go into labor with that alone and not have to pitocin. For some it just softens the cervix so you don't have to use as much pitocin. For me it did nothing lol just made me cramp and uncomfortable and my cervix stayed exactly the same. Good luck. Pitocin isn't that horrible like everyone says. I had all three of mine induced because of my blood pressure. Two of those no epidural. Good luck.
It softens the cervix so the induction will have a better chance of success. And yes, you could go into labor on your own at pretty much any point when you're at the end of your pregnancy. Good luck!