Emkana, oh Emkana, how i was in your shoes 3 years ago.
My boy did not say a "real" word till he was 3.6 years old. But even before that we never lost faith that he would speak, even when everyone around us was so intent on believing he would not speak.
Your child is still a baby and has so much growing to do. Is there anything physically that is preventing him from using his mouth, voicebox, tongue, etc?
If not then there is no reason why he will not speak.
If you enter down the "pecs" and makaton road, you have made (or others have made) a value judgement about your child, that he will not speak. I personally despise pecs mostly because the teachers/persons using it, dont know how to use it, dont know how to phase it out, etc etc. But moreso i despise it because it is part of a belief system that our children may not talk, so hey, lets give them a few pictures.
We fought for a year with our SLT (who was useless) about Pecs. I wouldnt allow them to be used at school and certainly didnt use them at home. We spoke to our child and presumed competence, that it was only a matter of time before he would speak. If he cried we asked him to try and verbalise what he wanted, even if it was only one syllable or even if he just pointed to something.
I personally feel pecs holds our children back and makes it easy for teachers to "handle" our children in school because they DO NOT have the time or inclinination to give our kids what they need 1:1 full time attention.
opinionated me?
Really start thinking about what others think about your child's difficulties and why they arent doing all they can to elicit speech, not cards, not sign language but real verbal back and forth communication. It starts with developing eye contact and motivatoin for the child to speak.
pecs will never NEVER develop functional communication, it only provides a means to an end, i.e. a way for the child to "get" something. I despair at the number of children who grow to adults using pecs when they could have developed speech if they were given the right amount of time, love and understanding.