I have PCOS and my waters broke naturally in bed at 1am in the morning. I tried everything I could to get my contractions to regulate and establish labour but unfortunately I had a stubborn bubba on board who needed a little hand to get her out so I had to have the synto infusion.
It is completely possible to go into labour naturally with PCOS. I know heaps of women who have (I work in midwifery).
Good luck