Zero words at 28 months

My 28 month old son says zero words - MAYBE one word if you consider “ma ma”. Although he uses this mumbling for anything and everything.

He uses a lot of grunts and pointing mainly. I think his receptive language is adequate as he seems to know basic terms like go get your water, where’s your ball, let’s go eat, time to change your diaper, etc…

His pediatrician doesn’t seem concerned at all and says we will reevaluate where he’s at at 2 and a half. Well I don’t see him improving much by then and would like for him to go ahead and start with speech therapy. I’ve called a different pediatrician for a second opinion, but we haven’t been to that appt yet. But I’m sure we will start speech very soon.

Has anyone else been at this point with their toddler? Good outcomes? Not so good outcomes? It’s hard for me not to worry about his development. He was also a very late walker. He didn’t start walking consistently until about 18 or 19 months.

I’ve been trying all the things at home to try and get him to say literally anything but he just doesn’t act interested. Almost like he doesn’t even know how can TRY to say the word. He still just has baby babble.