I have not taken Prometrium but I have taken progesterone suppositories.
I have taken it with my past two pregnancies and both have worked out to healthy babies and healthy levels ;) Im currently on it again for this pregnancy.
I took prometrium for my first pregnancy and had no problems at all. I took it for the first 12 weeks. The only side effects I really had was it made me really sleepy and I would sometimes have hot flashes. It IS really expensive :-(
I didn't take prometrium with the pg I lost, I did with the next pg and got my son Parker. My doc knew we were ttc so he wrote me an rx for me to start as soon as I got my bfp. I'm currently at 7w2d. I really feel like it works. It does make me drowsy and I have more cm but I totally think it's worth it.
Hope it works for you too!!
I am taking Prometrium as well, this is my first time.
Thanks for the responses.