My 14 month old son has not started walking yet. He cruises around holding onto the furniture or my hands, but sits down immediately if I let go. He loves to stand up, but only when he's holding onto something. He is very tall and has always been in the 100th percentile for height and weight. Sometimes I wonder if that could be affecting his ability to get moving on his own. Should he be walking by now? What age is late and should I be worried? Thank you for your advice!