bleeding after period during sex

My period was supposed to end two days ago. I was at that stage where all I had was brown discharge. I've been at that stage for three days now. This usually only lasts one day for me. This didn't seem that suspicious to me but today while I was having sex I had bled on him when he pulled out. This blood was light red and even had a small blood clot in it which seems like period blood to me and not blood from a sex injury. After that I could feel more blood coming throughout the day just like a period. I don't know if there was leftover blood and penetrative sex made it all gush out or something but has anyone had an experience like this before? Has anyone had the brown discharge at the end of your period for an extended time? I also use a menstrual cup if that matter