If your period is clean for three days and you bleed again, you may bleed during ovulation, which usually lasts for 2-3 days. However, if polyps, cervical cancer and other causes of bleeding, bleeding time is uncertain, may be 3~5 days. When estrogen level drops during ovulation, there is a possibility of transient ovulation bleeding, at this time, the amount of vaginal bleeding is relatively small, usually 2~3 days clean. However, if the bleeding is caused by cervical cancer, cervical polyps, cervical erosion, precancerous lesions, etc., so that the bleeding time is variable, sometimes manifested as bleeding after coitus. If the bleeding is relatively small, it is 3 to 5 days. It is also necessary to determine the cause of bleeding and go to the hospital for endoscopy to confirm the diagnosis. Keep your vagina hygienic and change your underwear frequently.