I have this problem but I don't think it's oversupply. I didn't have enough milk in the beginning & gave in to supplementing. I only supplement now a couple times a day. But maybe he's frustrated that not much is coming out. I have actually sprayed a couple times but only when I squeezed the nipple to see if there was milk. He gets a lot of gas, too. I wonder if he's not allergic to something I eat.