Dont worry, but do get him assessed if you and his daddy are not understanding him very well. My DS finally got assessed around 2 - 2.5 yrs and it was when the therapist asked me do we as parents understand over or under 50% of what he says? That I realised we understood less than 50% - and by that age thats not so good. The therapist can tell if he needs it or not, some kids are hard to understand but are making the right sounds for their age, mine wasnt . They concluded he needed help said they would wait till he was 3 yrs to start, as anything before was too tricky for the kid etc. Ds spent 2 yrs with therapy and has made a big difference for him and for us and others understanding him. Its great now he is at school he knows how to self correct alot too.