Progesterone or not?

I have had 2 miscarriages in the past 6 months. I am now pregnant with my 3rd. The dr has ran all sorts of test & so far they have found nothing wrong. I have read many stories of women taking pegestrone after miscarriages to prevent having another even if there pegestrone levels are normal. Has anyone had miscarriages and taken pegestrone and not had a successful pregnancy?