Hey Sal,
Congrats on your pregnancy! I found your post doing a Google search on high nighttime cortisol and pregnancy. Your story is very inspiring as I am 42 and have had pretty much the same experience as you have around hormones, and getting better with supplementation. I don't know about taking herbs during pregnancy but I'm sure your ND will. However I do know that keeping your progesterone level elevated is extremely important to keeping the baby. Progesterone is the gestation hormone and helps support the pregnancy.
Thank you for sharing and best of luck to you!