Three year old just doesn't seem interested in potty training

[WildWombat]

At 37 months it can't possibly be too early to train, can it? DS has good language and can communicate well, but he just doesn't seem to care if he wets himself or poos on the floor. He just carries on playing and doesn't even let us know it's happened. Is that a sign he's not ready? I don't want to push him and make it worse, but surely by their third birthday they ought to be able to understand, even if there's the odd accident sometimes? Feeling completely clueless and defeated already and we've hardly started. Any advice?

Are you following a particular method? I'd go with Oh Crap. I'd also expect it to take several weeks and prepare accordingly.

Does he actively poo on the floor or does it fall out (if you see what I mean?).

I don't really believe there's such a thing as being ready - this is a life skill that you, the parent, are teaching your child. It can be taught at any time (look up elimination communication!) - but of course it's easier to explicitly teach children when they have good understanding.