I want 4. Fiance wants 5+
I'm 22. Wanting children would make an insane person.
This is the correct answer. Maybe it'll happen at some point, but it's certainly not something I have any interest in now.
There are pros and cons for having kids young, probably more cons overall, but the pro of being young enough to enjoy life after they leave is a huge one. It seems like it would suck to be in your 60s when your last kid leaves the house. It's probably best to wait though.
Fertility issues is the other big one.