We always said 2 but then I started to want a 3rd... The arguments were horrid. We really went thru a rough patch.
We ended up having 3 - and dh is really happy to have him, but it took a lot of compromise and understanding from both of us.
I wouldn't have divorced him over it, but I do think that then all the other things that grate on you about your partner start to bubble up and that's when the thought of leaving each other starts.
For me I think I would have resented him for the rest of our life (or at least a reaaaaly long time) if we didn't have. 3rd.
No regrets. He is a beautiful baby, it's hasn't been easy but I believe for our family including our older kids, having him was absolutely the right thing to do.