At some point, you or your baby decide it is time to stop breastfeeding.  Sometimes you are just not that into it anymore.  It becomes annoying or you just feel like you want your body back.  Perhaps you are trying to conceive again and you need to take medication that is not safe when breastfeeding.  Or, you could already be pregnant and nursing your baby has become a bit of an ordeal.  It doesn't feel comfortable anymore, it is making your nipples really sore, you can't handle your toddler climbing all over your belly or perhaps you are nauseous a lot and spending too  much time with the  too enjoy breastfeeding anymore.