I want to become a nurse, but the sight of some things creep me out?Is the normal for those in the medical?

I am in grade 11. I want to become a pediatric nurse. My little brother sliced his head open hours ago because a neighbourhood dog bit him.. When I watch shows on the television about "life in the ER" and stuff like that.. I'm usually ok. Is it just because it was a family member or because they are close to me? Or am I physically unable to handle these kinds of things in general... should I still go for my dream job to become a pediatric nurse? Or should I give up because I can't handle it in the future.. Maybe it's also because I'm young....? Do some doctors get nervous or feel discusted in some of the accidents that have happend to their patients? Is this at all normal? Please help thank you!!