help! 4th pregnancy/ progesterone

Hi, I've had 3 miscarriages and just found out today that I'm pregnant again. It's so hard to be happy! Because I'm scared the same will happen but I am trying to relax. I'm wondering if the doctor would give me progesterone as I've read they think it helps reduce the risk of miscarriage. I'm in the uk by the way. I'm not sure how far I am as the last time I bleed was the 8th of Jan but it wasn't a full period it was a couple days of medium to light spotting.