seems your Dr isnt using much understanding to your situation.From what i remember, low progesterone can cause a miscarriage BUT it can also be a sign of a miscarriage that is inevitably going to occur KWIM? So if you are having an inevitable miscarriage a progesterone boost wont help but if the miscarriage is due to low progesterone then the pessaries may help that until everything kicks in and starts producing the 'good stuff'

Is it possible you can request a scan before they make any further decisions?

If a miscarriage does occur it wont necessarily come away on its own. We did the wait and see approach and waited 5 weeks and still nothing.

Crossing everything you have a sticky bub in there.