Bleeding after sex..

Over the past month I have bled a couple of times after having sex with my boyfriend. We have not been rough and I haven't been dry. It is enough where if I was in my period I'd use a tampon. We have been together for almost a year and I don't know why it would start happening now. I am starting to get concerned, but it is embarrassing. Tonight it was really bad. I was almost asleep when something prompted me to check....sure enough, blood everywhere. I am calming down before I wake him up...it's so embarrassing. Does anyone have any advice? I don't use an IUD and it doesn't happen every time.