update 2!
He came back in and I asked if he was ready to calmly finish our discussion.
I explained to him that this was not someone he could be friends with. That by continuing to talk to her that it is the same as continuing the affair.
I explained that even if he had the intention of just resuming their friendship, that he had no idea what her intentions were. That this is someone that stalked him, faked suicide attempts, faked a pregnancy, drove by our house etc when she found out that he returned to his wife. I don't want that in our baby's life. I told him I was scared that she would come to the house when he wasn't home.
I said I didn't want to be dealing with labour and the birth of our baby and wondering if he was texting/talking/emailing her. He looked at me shocked and said he didn't want her to mar anything that had to do with peanut (that's what we call the baby)and he wouldn't even bring his phone into the hospital. He went on to say that the only people that need to know what are going on are the ones that live under our roof and he's not going to risk ruining the birth to tell other people about the birth.
This may seem small, but his phone is pretty much attached to him. He is always on it and I joke that him and his bff talk more on it than women (I'm good friends with his bff as well, and know that the majority of the messages are with him)
I asked him why he lied about having contact with her, and he said that he figured with everything that happened last year, a couple of emails and conversations weren't worth mentioning. I said that it was still a betrayal and that it caused me to not believe other stuff he says. That my trust is broken, when it was shaky to begin with. I told him he needed to tell me about every contact with her, like he did when the affair first ended. I don't care if she says pass me a pencil, I want/need to know about it. I need to see every email, text or whatnot he receives from her.
I told him that he needs to choose between being friends with her, or being a husband to me and a father to peanut. He said of course he chooses me and peanut. I mentioned divorce/separation and he said he never even thought of it. I calmly said that I was the one that thought of it. I think that shocked the shit out of him. I've always been weak, and fought for our marriage (and we've been through a lot) but I said I need to think of Peanut, and I'm not bringing her into a house with negativity.
I said that he needed to write her an email and tell her that he will not have any contact with her ever again. That he will not be telling her about the birth of our child. And that he needs to show it to me once it is sent, or Bcc/CC me on it. He has agreed to bcc me. He's working 7-1900 today, so I will be waiting on that.
When he left for work this morning, I pretended I was still asleep and he came in and told me he loved me very much and was very sweet and affectionate.
I know we still have a long road ahead of us, but I'm hoping we will make it work. Once I get a copy of his letter, I will be ready for this baby to make her appearance!
Thank you all for your thoughts and prayers, they helped! Otherwise, my emotional pregnant self wouldn't have stayed so calm and I would have freaked out and we wouldn't have resolved anything.