I knew I wanted a kid/s but often thought about waiting for the "right time". I then realised there's no right time... My main driver was not wanting to be too old so I can throw a ball, run around etc. A child is both the most amazing and most stressful thing in the world!
I know some people much older than me that never had children. It's not really a topic that comes up but I get the impression it's by choice, however, you get to a point where that choice is taken from you anyway.