My son is 2, will be 3 in January. He is always talking and says a few words but nothing too recognisable. No short sentences or 2 words together. He is very good at ABC and counting up to 10 and understands instructions etc.. HV has mentioned getting him assessed for autism but his nursery are saying he's doing well as he is. No issues or signs regarding autism. Just wondering at what age do i need to consider this?