Bleeding on the second day after ovulation is bleeding caused by the change of hormone level in the body after ovulation, which is called ovulation bleeding. Generally, the level of estrogen in the body will decrease after ovulation, so that the endometrium loses the support of estrogen and sheds. Some women may show a small amount of vaginal bleeding on the second day after ovulation, which may be accompanied by slight discomfort in the lower abdomen, and generally lasts for a relatively short period of time, and most of them will disappear gradually after 2~3 days. However, when there is persistent vaginal bleeding, it is necessary to go to the hospital. Women with fertility requirements can be instructed by their doctors to have intercourse through ultrasound monitoring of ovulation to improve their chances of conception. Women who do not have childbearing requirements can also choose safe-period contraception by calculating the ovulation period, but this is not very reliable, and it is recommended to take oral short-acting contraceptive pills and other methods of contraception.