I'm currently 9 weeks pregnant thank to an FET! Every week until 7 weeks, my progesterone levels had been at around 30. In my 7th week, it jumped to 77. My protocol at that point had been 2cc of PIO every other day and 3 capsules of prometrium daily.
My RE told me they would start weaning me off progesterone at that point. They called in an order for hydroxyprogesterone (which I think might be p17), and they said to start taking that weekly through my 12th week. They said to continue the PIO and Prometrium one more week, and then to stop. So at 9 weeks, I'm on the hydroxyprogesterone each week and that's it.
My clinic has REALLY high success rates - they were rated #7 in the entire country. So I do trust them. They also told me in the beginning they usually switch people to the weekly progesterone somewhere around 6 weeks, so I actually switched 2 weeks later. However, I'm not finding any other protocols like mine, and that makes me nervous! I need to sit back and relax, but it's hard!!