15 month old not walking, always on toes

My 15 month old son isn’t walking yet. He’ll cruise furniture and his play yard but its always on his toes. he is too tall for his walker and in the walker is on his toes too. he like to hold onto the wall of his play yard and jump on his toes. i only see him flat footed if he stands briefly. i have seen him stand up and take 1-2 steps to grab the wall but im just concerned about him not walking yet and the toe walking. someone mentioned to me he might need physical therapy because he should be walking already. anyone else experience similar? should i be concerned?