We started out using the bottles that came with the Medela Pump, and would pull the nipple out every few swallows to slow DS down. Our Ped told us to try a slow flow nipple. We tried Breast Flow, but it ran down the sides of his mouth and then he stopped removing milk and would just comfort suck. Then we tried Drop Ins and he guzzles them down. We are still pulling the nipple out every few sucks too. We are using slow flow... Are we missing something?