I would strongly recommend that you carry on with the speech therapy. A child's mind is like a sponge and it soaks everything it comes in contact with. Given time, fruits of therapy will show. I say this because I was a severe stutterer a few years ago but with therapy, albeit irregular at first and regular later, I have improved a lot. The biggest mistake one can make is to let the child's stuttering be in the hope that they shall grow out of it. We could not be more wrong. How many of us grew out of therapy? When I have children, I plan to send my child to therapy whether they need it or not, if anything it'll help them speak clearer. What you can do is supplement therapy at home by reading to him, very slowly and articulating each word. I'm sure you know the basics, but parents should avoid completing their children's sentences and give them as much time as they need to express themselves. You might also want to start noticing patterns in his stutter. Say for example, maybe it's more with vowels or consonants. At the age of 3, if I were you, I'd just start doing fun exercises around the house. Such as prolongation of vowels. So every morning and before he goes to bed, you can start practicing AAAAA, EEEE, etc. That's my 2 cents. But I would urge you not to take your child out of therapy. I am not familiar with the program that you're referring to, but until you can seek alternative professional help or feel equipped and confident enough to tackle it at home, you must carry on with it.