Help!! Not growing - IGUR 😭😭😭

Blueberry is grown at a rate the doctors like and they want to take him out at 36 weeks 😢😢😢 while my sister and I were both born at 36 weeks I'm worried cause he's so small and ideas on how I can help boost his weight a bit.... Old school Puerto Rican ladies suggested avena (cream of wheat) they even told me how to make an oatmeal infused water that was given to women who were pregnant. Anyone else hear of this or know any other suggestions?