A: Producing more breast milk than your baby needs is a great problem to have. When it comes to breastfeeding, it's hard to define "normal," since our bodies, our circumstances, and our babies' needs make for very unique situations. In my experience as a physician, more breastfeeding moms worry about producing too little milk, especially when they start pumping in addition to nursing. That's probably why you got the advice to never throw out your breast milk. To moms who struggle to produce enough, it's more precious than liquid gold!
According to the Centers for Disease Control and Prevention, a mother's breast milk can be safely stored in the freezer compartment of a refrigerator (5°F or -15°C) for 2 weeks. If you have a freezer compartment with separate doors on your fridge (0°F or -18°C), your breast milk can be safely stored for 3 to 6 months. If you have a chest freezer or an upright deep freezer (-4°F or -20°C), breast milk can be safely stored for 6 to 12 months.
You might already be labeling the storage containers with the date of breast milk collection; this will allow you to use the oldest milk first or discard it if you won't be using it safely in the future. If you've got plenty in your freezer and you're still able to pump and store more, don't feel bad about discarding the oldest milk in your freezer.