I am a 24 year old female. I was in the middle of a sexual act with my partner when I started to bleed without any pain. I thought that My periods have started as they were due in a day or two. But now 3 days have passed since that incident and there has been no bleeding/discharge at all since then. There is no pain either. I don't know what is going on. I undertook a pregnancy test and it came out to be negative. This is the first time I have experienced such thing. Please help me understand the situation. Thank you.