I'm at the age where, if we want to have kids, we have to do it now or else it will be too late (if it isn't already).
If we do it now, then my library career will be on hold indefinitely. But as long as my other half is happy to support me financially for at least the next 5 years, then I'd probably be happy to play housewife (and catch up on the reading and painting?).
If we don't do it at all, we'll be able to maintain a reasonable lifestyle, I can get qualified, and maybe improve our lifestyle. I may end up regretting not having kids, but I'd have a nephew and niece to lavish attention on.
I think what would be the worst would be to decide to go for it, get all psyched, then find that it's no longer possible.