15 month old shows NO interest in learning to walk.

My husband and I have purchased different types of walker toys, and still my 15 month old son shows no interest! He cruises along tables, and couches, he even climbs things, but will NOT walk alone or with a walker. We try daily to get him to walk with us by holding up his hands, having him hold onto our arms as we sit a little distance away... I feel like we have tried everything!Now, he does sometimes walk with a walking toy, but it only lasts a short distance, and I've noticed that he doesn't always bend his knees... is this normal?My doctor has referred us to a physical therapist, just because he isn't walking. I've tried to bring up the not bending of his knees, but she just blows it off and tries to turn it around to make me feel like I'm the reason he isn't walking at 15 months.He stands up in his own, with no balance issues, he dances in place, he climbs, and he walks along furniture, so I don't believe it's because his legs aren't strong enough. However, since we have private insurance, going to PT is going to require a hefty sum out of our pocket (our insurance sucks!). Should I get another opinion, or try something different? I'm at a loss here. Obviously we will go to PT if it's needed, but she didn't even examine his legs before referring us.Thanks reddit! via /r/Parenting http://ift.tt/2DzfBm7