Breast-feeding can be used as a method of birth control, called the lactational amenorrhea method (LAM). However, three conditions must be met to ensure its effectiveness:
When these conditions are met, LAM has been shown to be 98.5% effective.1 However, many doctors recommend that you also use another method of birth control.
After 6 months, even if you are breast-feeding exclusively and your period has not returned, you must use an additional form of birth control if you do not want to get pregnant. You can get pregnant before your first period. This is because you ovulate, then have your period.
At any point during breast-feeding, use a reliable method of birth control if you do not want to get pregnant. Many methods are safe to use while you are breast-feeding, although some are more reliable than others. Options include:
Fertility awareness is not recommended for birth control during breast-feeding. This method is less reliable and difficult to manage than other forms of birth control, especially with the sporadic ovulation that may occur while you are breast-feeding.
For more information, see the topic Birth Control.
Citations
WebMD Medical Reference from Healthwise