Acid Reflux in 3 month old.

So Ava drinks Enfamil A.R (acid reflux) which has rice Starch in it. I noticed that it helps a little but she still spits up. I also burp her in between and after feedings. However, when I put a little bit of rice grain in addition to the formula, she does even better! My issue is that it gets costly. Does anyone know of remedies or formulas that can help with her Acid Reflux? She sees her pediatrician this month so I want to research everyone’s solutions and make a list to present to him. He doesn’t want to give her medicine for the AR.