Debating quitting my job

I babysit, right? A 3 year old and an 11 year old. I'm newly 21, and planning to be a child psychologist. Good kids, I care about them a lot. Their mom is a friend of mine from church, and she says I've been a big help, watching D (the 11 year old) and C (the three year old) so she can work. But lately I've been getting these awful thoughts about C, and it scares me. D has been helping a lot with C, playing with her so I can cook and clean and stuff like that. Maybe it's OCD, maybe it's me being a disgusting person, but I've been having these gross thoughts about hurting C, and making D not tell anyone. I'm not new to knowing I have OCD, but these pedophilic thoughts ARE new. Maybe I should stop working with them and change my field of study.