Generally, menstruation occurs about 2 months after weaning, because while breastfeeding, the body’s lactogen is always at a high level, and under the stimulation of higher levels of lactogen, the ovaries do not ovulate and do not secrete estrogen and progesterone cyclically, so clinically, menstruation does not occur. After weaning, the prolactin level gradually decreases, allowing the ovaries to resume ovulation and the cycle to occur, allowing menstruation to resume. One thing to note in particular is that while breastfeeding, although high prolactin inhibits ovulation, ovulation can occur occasionally in clinical practice, so occasional ovulation may occur before menstruation. Sexual intercourse should always be done with good contraception to avoid causing pregnancy.