Ear tubes question?

My son had tubes put in his ears 3 weeks ago he is 20 monthes he has had a lot of ear infections and doesn't talk he says 5 words mama, dada, papa, gone and juice. I thought that after the tubes he would beable to hear better and his talking would improve right away but I have never went through this before so if anyone has please tell me your story. I have a message into the doctor about a hearing test. He had one already they said he had fluid in his ears so he had temporary hearing loss and the lady that did the test said as soon as the fluid drains out he will start talking right away so I thought that ment shorty after the tubes were in. Any advice?