Bleeding after fingering

So I just finished my period yesterday (Tuesday) and today (Wednesday) I went to my boyfriends house. We ended up messing around a little bit and he fingered me, which was amazing btw, and now there's brown discharge. I'm slightly embarrassed because I'm not sure if it started while I was with him or not. I not a virgin by any means and i don't think it's a cute or anything like that. I guess I'm asking if it's like "old blood" that was just hanging out or what and maybe if some one could explain this too me a little bit. Thanks much 😊