I was being fingered and the guy got blood on his fingers. I'm not on my period, and I'm on birth control. No blood has come out of my vagina. Help?

"Hidden" bleeding. The vagina is great at hiding bleeding within its spaces. The "fingering" may have been a bit rough and traumatized the vaginal mucosa(lining). If you insert a tampon and find blood on it when it is removed, you will validate this answer.