It's very normal.
I've never wanted kids either, I was once a camp counselor for little kids back when I was a teenager and some of the kids weren't potty trained and I would never go near any of the kids who wore diapers, changing a little kids diaper repulses me, and some of the kids were really nasty.
I'm now 45 and still I never want kids, and I'm happy with my decision about never wanting kids.
Also the ones who throw tantrums in public really make me uncomfortable, I could never deal with a kid who behaves like that.
I also don't want to risk getting pregnant in my 40's, what if the kid ends up with a birth defect and I don't want to take care of it for the rest of its life, who needs that? I sure don't!