I was on it @RunnerGirl123. My clinic wanted me to stop at 8 weeks but I insisted thatI wanted to carry on the 12 weeks so they prescribed me more. I carried on with two a day until I got down to my last 5 and then went one a day and then stopped so I've been off them for over 2 weeks now and everything is fine - no spotting, no issues. Had my 12 week scan (which was 13+1) since then and baby was fine so that was reassuring.
My original fertility nurse told me that my ovaries were back to their normal size (after IVF) and were producing their own Progesterone so I didn't need it beyond 8 weeks, and by 12 weeks the placenta takes over all hormone production for baby so I'm not sure there is much point in taking it beyond 12 weeks if that is any reassurance?