I am an ivf person, pregnant with twins. I was on crinone gel for the 2 ww and then nothing, I have very good levels, at 6 weeks my progesterone was 470. Beta was 21100, we were totaly surprised at the scan a few days later to see twins.
I was only on progesterone for about 12 weeks. I didn't have pcos though, our reason was "unexplained infertility".
I got my BFP through IVF also because of PCOS. While on the 2ww, I was on progesterone in oil, estrace (estrogen - vaginally) and baby aspirin. The estrace was stopped once we saw a heartbeat, which was around 6 weeks. The progesterone was stopped around 10 weeks. I'm still on the baby aspirin which I will stay on until about 25 weeks according to my ob. Hope this helps!