Course Selection Help ?

Okay I'm in Grade 10 right now, and I need to select my courses soon. I'm thinking about being a pediatrician and I'm having a hard time deciding what courses to choose, and I know I need science courses. Right now I'm thinking of taking Biology, Chemistry, and Health Care. I don't know about Physics though, because I'm really booked on picking my courses. Should I take it? I live in Canada by the way.