So babies are born with teeth, all though uncommon at 2 1/2 its not unheard of.
Its too early to tell if they are going to be a lefty or righty, my daughter used both hands equally, some times left would be more dominate, others she'd go with her right. He also might use his left because he's wanting to keep his right free for other things. Or when in the womb that was the free hand most of the time. But again its way to early to tell that kind of thing, have to wait for the mortar skills to kick in.