Your ovulation cycles will change while breastfeeding. The pituitary gland releases prolactin when you breastfeed. Prolactin stimulates milk production. The more prolactin the pituitary gland releases, the higher serum levels reach and high serum prolactin levels can suppress ovulation.
Unfortunately, the threshold for ovulation suppression is different for each woman, so there is no set rule as to how frequent a woman must breastfeed to suppress ovulation. Some women find ovulation cycles return to normal as your infant ages and stops breastfeeding as often.