Some mothers have too much milk before their breasts have adjusted, while others have too little. This does not necessarily mean that you will be less efficient milk producers later on. Most can produce enough milk and are able to feed a baby normally after two weeks or so. But during these few weeks, while you wait for milk to increase, you are in particular need of support, encouragement, and supervision, so that you do not give up.
If your infant loses too much weight (more than 10% of his birth weight), or shows signs of dehydration, you can give the child-expressed breast milk (EBM) from the Breast Milk bank so that the energy needs are met. Or, if EBM is not available, you can give carefully controlled supplementary feeding, which of course is not as good.