I am using a surrogate due to complex congenital heart defects and we are currently 10 weeks pregnant with TWINS!

My husband and I had discussed me inducing lactation long before we transferred and agreed it was something I should attempt to do. I had a friend look up my meds and was told that all were "safe" to use while breastfeeding.
Two weeks ago I went to my GP (I don't have a GYN, mostly out of laziness) and told him I wanted to try the protocol. I brought with me the book "Nursing Mother's Handbook" to show him the protocol. He made copies of those pages and plans to do some research and get back to me. However, he went ahead and prescribed the Ortho-Novum to go ahead and start taking, as I need birth control anyway. I happen to already have some domperidone a friend ended up not needing, but haven't started taking it yet. The babies are due July 2nd. I had been planning to start the protocol by Dec. 11th (6 months prior to the 37 week mark).
Last night I was reading my "Nursing Mother's Handbook" before going to sleep. I got to a part that talked about medications and referenced an appendix, so I went to check it out. I looked up all of my medications and every one of them says that only small amounts are transferred into BM and they are considered "safe" (I knew this already, from talking to my friend, but it was nice to see it in writing).
However, I also read a part about premature babies possibly being affected by smaller amounts than term babies or babies a couple of months old.
So that got me thinking... My babies will come at least a little early, I'm sure. So will all of my meds put them at risk after all? Also, the fact that I take SO many meds, could it cause a problem even though individually they're considered "safe"? I, of course, plan on talking about this with my doctor, but thought I'd see if you have any experience or advice.
Thanks,
Niki