It is possible that the bleeding during intercourse was caused by friction resulting in small tears inside the vagina. This can happen when there is not enough lubrication during sex. Using a water-based lubricant can help prevent this issue in the future. If the bleeding continues beyond your normal menstrual period, is heavier than usual, or is accompanied by fever, severe abdominal pain, or unusual discharge, it is advisable to consult a doctor. Additionally, if the sexual encounter was unprotected, it is important to get tested for sexually transmitted infections in the coming weeks or months. These steps can help ensure your health and well-being.