Potty Learning is it too early?

[mommypooh]

I have a DS who will be 17 months soon, he tells me he needs changed and most of the time he hasn't gone yet so if I take him to the potty he will go. He has been spending all day outside in swimming trunks with no diaper and will use the little potty I put out for DD. He wakes up dry in the morning, and after nap,

Should I go forward with training him or should i just wait.