I don't think it does for some people. I for one would love a fourth. I love being pregnant, don't mind labour, love BF, and it makes me weep my babies are all growing up.
But rational me knows it's not feasible, and I have to live with that. Same as I wanted a pony when I was growing up and would keen in a crazy person way until my dad would shout at me. I eventually (years later) accepted I was never to have a pony.
Life goes on!
ETA I just noticed you asked if it becomes regret- I don't think so, it just becomes acceptance.
This post has been edited by thecleanowl: 24/01/2013, 02:46 PM