Hidden.

So, here's the issue. My boyfriend is going through a divorce (it's been a year and a half and it's still not done). We recently found out we are pregnant (9 weeks!) I was excited, but talking with him. He doesn't want anyone to know. He has 3 kids from his previous marriage, and he doesn't want their mom to find out. We have full custody of the kids, and it would be hard for her to fight for custody (she likes the club's, and alcohol) but he is concerned about her fighting and lengthening out the divorce further. Where me, I want to tell everyone! It's my first pregnancy, my first child and my first everything. I love him, but when I bring stuff up, he just says, "I've been through this before, I know". It's frustrating because I want this to be special, but he is just like, oh, another one. I told his Dad I was pregnant, and his dad is excited. But, my boyfriend became furious with me. Accusing me of lieing to him, and I must be cheating because if I'm willing to lie about little stuff I have to be lieing about big stuff too. His ex cheated a lot. So, I know it's on his mind. But, I feel like I am living in her shadow with this pregnancy and I just don't know what to do. Any advice?