What Causes Blood To Come Out During Intercourse?

Hello, i am a female and recently while engaging in intercourse with my boyfriend i had a little pain and then we noticed a little bit of blood. it was just the tiniest amount and we stopped and i was able to engage in intercourse the next day. i have been reading up and i believe the most probable cause would be a small vaginal tear. I wanted to know if a doctor thinks that this is what it could be. I had described the pain to my boyfriend as a cut before i read about micro cuts and it seemed to go away pretty quickly. The pain was minimal and it felt like maybe there was a little too much friction.