don't mind what other people tell you! You know your child the best and you should do whatever you feel is best. My DD is 19 months and very quiet. She has about 2 words that are able to be understood properly. I know it's just her. try to tune out the negative feedback regarding your parenting. According to most mums (trying not to be *****y) Their child does X,Y,Z and will always be better then your's but that's how they perceive them. Your son might not be doing "X,Y,Z" like another child but do "X,Y,Z" that another child doesn't.

HTH and GL