I recently began masturbating. tonight i inserted my finger and there was a bit of blood. there's none leaking out and it doesn't hurt. what do i do? or what does it mean?

In general, thats ok: First, I would recommend keeping a menstrual diary to keep track of your cycles. When that episode occurred, were you about to start your period? Sometimes, slight bloody discharge may be in the vagina before your period actually starts. Second, remember that it is possible to have small abrasions or nicks if your fingernails are long or with very aggressive stimulation. I suspect all is ok.