I thought I was going to have 5...but are so very happy with 3. I can't remember when I so firmly decided on that though.

I had a m/c between 2 and 3, and didn't relax properly or even really bond with her in utero until she was in my arms. I think it helped that I never, EVER wanted to go through that stress again. With the others I immediately relaxed around the 12 week mark.
Even with the zen waterbirth I had with DD, I do remember thinking nope, that's it I'm done!

And because of that, I celebrated my last baby, like Just Me I breathed her in....in a different way. I felt in my heart she completed the family and somehow I was so much lighter/laid back in the way I parented her and gave myself free rein to spoil the baby of the family