K.M.
I was put on Prometrium for pregnancies #3, 5, and 6. The first two pregnancies I did not take any supplemental progesterone and they both miscarried. Number 4 was ectopic so nothing would have helped it. Anyway, I had no side effects whatsoever except carrying the babies to term. That in itself would have made any side effect worthwhile since it had been six years since we had started trying...I DID NOT want another miscarriage.
Have you had a successful pregnancy before? If so, this miscarriage was probably just one of those unfortunate events that happen to 20-25% of women. If this is a pattern though, I wouldn't hesitate to accept any help at all. And if you take the progesterone and miscarry again, then there may be some other underlying problem.
I wish you the best!
K.