Cohash is used to stimulate labor and soften the cervex. Most midwives beleive it to beneficial but the risks associated for it are primarily durring early pregnancy. I wouldn't reccomend you take it without a midwife to consult on the dose.
One thing you might want to think about is herbal remedies durring contractions, like skullcap. I would suggest useing only herbs that are considerd foof, tonic or herbs.
As for what you are taking it seems right and there is not much that I would reccommend exept maybe some dandylion leaves added to a daily salad.
For preparing for nursing I would suggest Blessed thistle, it will increase in enrich the flow of milk. But beware, if you are like me you need no help at all with your milk supply. Wait on this till after your milk comes in and then see.
Lady's mantel is helpful in settling the stomach as well as keeping you from hemoraging durring childbirth. This was very important to me because women in my family have a history of hemmoraging.
Nettle leaf is good if you have insufficiant iron.
I fyou wouold like to do most of these things on your own I would recommend owning "Herbal Healing for Women" by Rosemary Gladstar. It is invaluable and will ansewr all your question as well as give you recipes for everything you could possibly need.