Moms returning to work often worry about not having enough milk saved in their freezer. The good news is that the only day you need to plan for, some days in advance, is your first day back at work. Therefore, two weeks before returning, pump one time each day after a morning feeding, when milk supply is the highest, and place your pumped milk in your freezer. On average, breastfeed babies drink one ounce per hour, so caculate the amount you will need for day one based on the number of hours you will be away from your baby. Pumping two weeks in advance is likely to result in enough breastmilk but if you rather have some extra, begin pumping sooner. Finally, once you're back at work, not only will you be pumping for the breastmilk your baby will drink the next day, but pumping will also keep your production steady.