M.G.
I am a PT in Early Intervention. While you may not need to "worry" 17 months is definately at the later end of the normal range for walking. I would recommend getting an Early Intervention evaluation if, for nothing else, peace of mind that their isn't anything going on. They can give you suggestions to help get him walking if he is not eligible for therapy. If you need more info on how to refer you can send me a message!