There's a massive advantage to having kids when your young (20s), even if you think you can't afford them. With hindsight, I would have married a girl 3-5 years younger than me & pumped out 3-5 kids in my 20's. The earlier you meet your partner, the less emotional baggage you both have.
when I was younger my concerns centered mostly on making the correct decision in choosing a spouse, and delaying children long enough to have a successful marriage and supposedly not be as broke. now that we've done that, I can see the value in having kids younger and utilizing more of the time were given to reproduce. that being said, 20 mins with a 20 year old will make me grateful I married later haha