I was 24 when DP got pregnant, she was a couple of years older 27.
Do I feel that maybe we missed out on some stuff? Yes, a little bit, but more the early stages of our relationship rather than being young and free and single (We'd had DD before our relationship was a year old!)
However, DD is now 18, and off to uni in September, and I'm only 42. I look at all my friends with their toddlers and think "Thank fuck I'm past all that". I looks after my brothers 6 and 3 year old for a few hours and wonder how of earth a parent of my age copes with that all the bloody time!
When DD was born, yes, I thought "What the fuck have we done" a hell of a lot, but now, I wouldn't change a thing