If you've fallen out with family members why are they connected to your Facebook?
If they're not, just make the post friends-only and they can't see it.
You can also select audiences. If you don't want X or Y to know, you can omit them from being able to view it.
I dunno. Yes, it's your body etc but it's also his child and if he wants to do an announcement it seems silly not to let him just because you have the uterus and therefore some sort of veto.
My DH is very anti-Facebook and very private, so I am not allowed to post pictures of him, talk about him, mention him, refer to him on Facebook in any way even though that means I can't talk about, well, a big part of my life really. Yeah, OK, I get he's uncomfortable, but that's the thing with shared lives, shared news, shared anecdotes - they're shared and you don't get automatic veto rights.
I dunno. Just seems a sort of gentle nice thing to do, but then my FB is a drama-free zone and I don't have anyone on there I don't know and trust. I have no connections to people I would not want to see my news.
The compromise is he announces it on his page only, to his friends, because it's his news to share, and basically doesn't mention you at all, which is how I have to talk about my DH.