Four months after giving birth is during the breastfeeding period and it is possible to get pregnant. Irregular menstruation during breastfeeding may result in delayed menstruation. Breastfeeding will delay the recovery of menstruation after childbirth, which occurs about six months to eight months after childbirth, or in some cases, women resume menstruation after the full moon and will have normal ovulation. However, due to the less stable ovarian function after delivery, there are very few cases where there is no menstruation and ovulation, and pregnancy in this case is easily overlooked. Therefore, normal ovulation will occur during the four months of breastfeeding, and if no safe and effective contraceptive measures are taken it is very likely that pregnancy will occur. It is advisable to go to the hospital for an ultrasound or blood HCG test to determine if you are pregnant. The uterus is relatively soft during breastfeeding, which can easily increase the difficulty of abortion surgery, and there are certain adverse effects on maternal health and normal breastfeeding, so it is important to take contraceptive measures such as condoms after resuming sexual life after childbirth.