Brown residue on fingers after masturbating.

I haven’t had sex I’m YEARS. But sometimes when I masturbate. After I finish I’ll have like cum left on my fingers. And sometimes it will be brown, but I dont notice it until I go to wipe it off. Like what is that. Is it dried up blood. I know I don’t have any std’s or anything, I haven’t had sex in years and the one person I had sex with years ago he didn’t has any std’s so I’m tryna figure out like what is this stuff on my fingers like today I masturbated it is the 26th my period ended on the 19th could it still be like dried up blood or sum. And it’s crazy because when I pee and when I go to wipe I don’t see any brown stuff on the tissue. I added a photo so you guys could be the judge.