Depends entirely on your own body chemistry. Although the hormones that support breastfeeding do naturally suppress follicular activity, how long that suppression lasts varies from woman to woman, and you may not necessarily need to have your cycle return before possibly getting pregnant again (since ovulation occurs before a period).
In other words, if you don't want to get pregnant again anytime soon, breastfeeding should not be relied upon as a form of birth control. But if you DO want to get pregnant again, your cycle returns, you try for several months and have no luck, then weaning your first baby may be the only way to successfully conceive a second time. Some EBF moms will get their cycles back just a few months after baby's birth, others won't get a period at all until baby has started on solids and is taking in less milk, or in some cases until lactation has stopped entirely. Just depends on your body and how sensitive you are to your own hormones.