patience, just got back from the doctor. He told me he didn't see any problem in me stopping the progesterone cold turkey. I told him I wasn't willing to do that, and pushed him to take advice (I am the worst patient ever!).
He put a call through to the consultant on call gynaecologist, who said it shouldn't be a problem stopping it immediately, but if it would make me feel better, I could taper it off, so 2 a day for a week, then 1 a day per day. She said it shouldn't have any adverse affects on the baby. (Omg, baby!!).
I told him I was very worried about miscarriage. He said that if it happens, there will have been a good reason for it, and not to worry too much. I'll try!!!!