LR, yes, you are doing the right thing
If your GP is making you second-guess yourself, sometimes its best not to disclose that sort of info, KWIM? (If you feel particularly attached to your GP, that is... Maybe you could see someone who's more inclined towards your method of parenting?) Or just say, 'thanks, but I'm really happy with the way we're going'.
Plus, I reckon those drs who recommend CC techniques to parents who are happy with the amount of sleep they're getting are doing their patients a disservice - CCing is absolutely fricking exhausting. Both physically and mentally. You only do it if you feel like you have to, and have no other choice.

ETA: I do agree with Astrid. Drs who are more 'gently' inclined are few and far between. My dr was really good in that the only thing she said about sleep was, 'bah, mine didn't sleep through until they were at least 1... Perhaps they were older? I can't remember now!' etc etc. It really reassured me