Any surgery does not require stopping breastfeeding. If so, make sure again the incision is not made around the areola. You can continue breastfeeding after the surgery is over, immediately, as soon as you are awake and up to it. If, for some reason, you do have to stop on the affected side, do not stop on the other. Amazingly some surgeons do not know that you can dry up on one side only.
Mammograms are more difficult to read if the mother is breastfeeding, but can still be useful.
Discuss the options with your doctor. There is no reason that you cannot continue breastfeeding if you become pregnant. There is no evidence that breastfeeding while pregnant does any harm to you, or the baby in your womb or to the one who is nursing. If you wish to stop, do it slowly, though, because pregnancy is associated with a decreased milk supply, the baby may stop on his own. Illness in the Baby Breastfeeding rarely needs to be discontinued for infant illness.