baby with acid reflux?

I'm fairly certain my 8 week old is suffering from acid reflux. An hour or two after feeding he will make an unhappy face, scrunch up his nose and begin to gag and cough, then he'll make a "chewing" motion with his mouth, this happens rather frequently. He also gets super gassy even
If I burp him after every ounce and hold him upright after feeding. I told his pediatrician at his 4 week check up and he told me his digestive system is still developing. But, it's still Happening! He has his 8 week check up next week- anyone else have this issue? A friend of mine had to put her 8 week old on Prevacid.