What are the reasons for vaginal bleeding during menstruation?

Patient's question:

Medical history: None
Detailed condition and consultation purpose: Previously, my menstrual cycle was about 4 days long. This time, I had sexual intercourse on the fourth day of my period, but the next day, I experienced vaginal bleeding again. However, the blood was bright red, different from the color of my menstrual blood. I don't have any medical history. Could this be due to some organic damage? What should I do?
Thank you

Doctor's answer:

??????Hello, conception occurs during the ovulation period, approximately fourteen days before the next menstrual period. Based on your description, the likelihood of pregnancy seems low.
Pay attention to personal hygiene, change your underwear frequently, and avoid eating raw, cold, spicy, or irritating foods. Go to the hospital for a gynecological examination and receive symptomatic treatment. The occurrence of gynecological inflammation not only affects a woman's life but can also lead to gynecological diseases. Therefore, it is best to have a vaginal discharge test at the gynecology department of the hospital to identify the cause and receive symptomatic treatment. Additionally, pay close attention to personal hygiene and maintain cleanliness in the perineal area.