I'm so sorry for your losses. A LP of 8-9 days is a worry. I think alot of time we have an instinct for these things that some doctors just ignore. After my m/c, I had BT during my next pregnancy. I started spotting 5-6 weeks and my progesterone was low. I started progesterone suppositories and did not m/c. I have a LP of 10-11 days and figure maybe there's not enough progesterone, maybe there is. It doesn't hurt to take it JIC and if it prevents a m/c for that reason, then great. If there's something else wrong with bub, it won't prevent a m/c but at least I'll know I've done all I could.

I hope you get more answers from another Dr soon.