I need to feed my baby. I have formula on hand for back up. No matter how often I try to feed baby to the breast or pump to bottle feed, my milk is so low that baby is not getting enough. Was wondering if I can switch back and forth? I want to give her enfamil formula until I can pump a few bottles for her. Will this switch affect her belly/digestion? I feel awful having to supplement with formula but I'm desperate to keep her fed.