How to help my son?

How to help my son? Till 4 my son used to speak without stutter, but he was unable to pronounce his 'r's well; And so the new school gave him a lot of words that heavily uses 'r'. He started to pronounce 'r' but also starting stuttering while speaking. I myself stutter when I am very emotional, but it is not there normally. Everyone said it will go away on its own, now he is 11, he still stutters, should I take him to some speech therapy? I asked if he'd like some speech therapy, but he doesn't want to, he firmly believes in him, he is a very confident person, but for some reason the word therapy give a negative connotation Are there simple exercises that we can try out before therapy?