He can talk. He chooses not to.

DS can talk like the blazes. But then he'll point or babble at other times. Or just scream. It's so frustrating because he KNOWS the word, just doesn't use it. But that's normal behaviour, he can talk so no worries there.

At 18m DS has a lot of words and phrases, basic sentances, talks to himself (in babble usually) while playing - this is developmentally a bit advanced.

At 3 a child should be able to say words recognisable by people other than Mama (I'm the only one who can have a conversation with DS because other people don't recognise his words a lot, although agree with my translations) but some children are naturally quieter than others. Just because my DS doesn't shut up doesn't mean every child should be the same.

Maybe ask him for the word when he points, say you can't understand without words. If that helps all your worries will be over! A speech therapist isn't going to make a reluctant talker talk, but will say if he can talk and hear then he's fine.