I'm 11 and I don't want a sibling

I am 11 and I am my parents only hope of carrying on their family. I have no siblings and I know that when I grow up my mum and dad wish for me to have kids. But I don't want kids. I really don't want kids. They are just so...annoying. Yes, I'm just a child but I'm mature for my years. That being said I don't want a child or even children. I'm not that kind of girl that I always wanted to be a mother and have babies. I know that when I tell them I don't ever want to have kids they will tell me I'll change my mind when I'm older. But I know I'm not going to. I want to be child free. I know my family will be disappointed but I can't spend my entire life having kids and taking care of kids and raising kids just because my parents want me to. Am I the only person who is like me?