I don't think young or old is weird or abnormal. A lot of the time its circumstances. A lot of older mums (ie me) aren't in a position to have children earlier. I didn't meet my DH until I was 35. I was ready for kids earlier but the men in and out of my life either weren't the right ones or there were other things working against me/us, so it all happened much later for me.

Younger women might have a career that they have spent years studying for and only just begun, and want to pursue before taking time out for children. The good old thought that as far as women go you're born, go to school, get married to a 'good' boy from a 'good' family and have kids is thankfully a dead and buried belief for most. If you want a career you should definitely pursue it. Hey, even if you want to be selfish as some have called it and spent your 20s partying then you should do that too. Having said that, if you're young and you and your other half want kids now then go for it. What is right is going to be different for all of us, but nothing could be worse than having a child before you're ready just to fit in with either some social norm or with your partner's wishes.