When I was pg with #1, my thinking was "No way in hell is this baby going to change the way I live!" and I was calling around town to find the cheapest daycare that would take her the earliest. It was only because we couldn't afford daycare that I stayed home.
Then I decided it was the best thing for her after all. I figured that when she was three, I'd put her in preschool and go back to work. We weren't sure if we wanted to have another child or not.
When she was about 20 mos, we decided we wanted another child and got pg right away. So of course it wouldn't make sense for dd1 to go to preschool when I would have had to stay home with the baby anyway.
So then we had two kids, and I was feeling more and more like I would rather homeschool, and that even if we ended up sending them to private school, that I belonged at home so I could always be available to them in case they needed me throughout the day.
Now my thought is I don't care if I ever get back to work!

But I'll shoot for going back when they are old enough to stay home alone.