I never wanted kids either. I remember a conversation in high school with my friends (this was 40+ years ago) and they were talking about kids and I told them I never wanted any. They were Oh you'll change your mind. They were wrong I never did. I also had to nieces that I loved and spoiled and then sent them home to their parents. That's the best way to have kids.
I think I didn't want them because I'm selfish. I didn't want to have anything interfere with what I wanted. Kids are a lot of work. And there are some people that just shouldn't be parents....I think that's me.
You are not alone. I'm 60 and that was the culture when I was in my 20's. Get married have kids...live the American dream. (PS never got married either)