Breastfeeding more than six months to a little menstruation and then disappeared may be subject to postpartum hormone level changes caused by irregular menstruation. As a result of breastfeeding, women who are breastfeeding will delay the return of menstruation, or will not have menstruation during the breastfeeding period. The first post-partum menstrual period, when it comes for a little while and then disappears, is due to the post-partum hormone level changes in the body caused by the post-partum menstrual period is slightly irregular, and will usually return to normal after 1 to 2 times of menstruation. Although the return of menstruation will be delayed during the breastfeeding period, ovulation usually resumes 4 to 6 months after delivery, so although menstruation has not resumed during the breastfeeding period, there is still a possibility of pregnancy. For those whose menstruation resumes, the first period is very small and short, and when the next period is delayed for more than 1 week, the possibility of pregnancy should still be ruled out, so it is still necessary to take contraceptive measures during breastfeeding when having intercourse.