Along with the choice to breastfeed, the choice to stop is a personal one. If you feel the time is right to wean, then it is. Only you can decide what to do in your particular situation.
Most breastfeeding advocates recommend gradual child-led weaning. Abrupt weaning can be traumatic for your baby and uncomfortable for you. Generally speaking, a baby won't choose to wean earlier than around age 1. Lack of interest in breastfeeding earlier than that may be a nursing strike — a temporary refusal to breastfeed — or a lull as the baby concentrates on developing a new skill that takes his interest away from eating for a while. Most babies younger than 9 months happily resume breastfeeding within a few days.