Is it wrong that i don't wanna have any children?

I'm only 15 but I think it's one of the hardest things a woman can do.It's also because of the fact that my baby brother(6 years old)is a "difficult" kid,he gets sick all the time,he's spoilt,he nags etc. and this has influenced me in a bad way.I know there's a chance i'll change my mind in the future but i'm just wondering is it so bad?