You are not crazy. We knew we were done after #2 because I knew I couldn't cope with any more postpartum complications & suspected #3 might just cost me a kidney.
But i still cried they day he had it done. And we were careless afterward before he'd been tested to make sure it took. I thought I was pg again & cried even more when I found out I wasn't because it was the for real for ever end (and who cares about stupid kidneys, you can manage with one)