Hi, THanks for posting in HCM. I understand your concern. Dengue fever is known to cause decrease in platelet count, which can amount to hemorrhage at many parts of the body. Even after recovery from fever, the platelet count takes certain time to be back to normal and bleeding tendency might continue for some more time. Since you had intercourse during the recovery period, there might be a possibility of injury to vaginal mucosa or cervical mucosa, which has resulted in heavy bleeding. You should not mistake this for your periods. Since you say you had taken adequate precautions and had protected intercourse, chances of pregnancy stands remote possibility. Relax and kindly wait for your regular periods to happen. It would be better to avoid sexual activities for another week to ten days, so that it gives time for the platelet counts to pick up. Hope the information provided would be helpful. All the best.