Bleading while fingering, possible missed period

I was with my girl 3 days ago. I fingered her and she started bleading i think i scratched the inside with my fingernail. Problem is she said she wasnt in pain. 6 days before i had sex with her... Now the reason im scared is im afraid its a lighter period indicating a possible pregnancy. It has now been nine days since i had sex with her. 4 weeks ago she had her period on a wednesday. Now she hasnt had her period yet and tends to get them on mondays. Me and her both are scared i have a few quiestions:

Do u think that it was a light period and not due to me cutting her? She claimed he wasnt in pain and the bleeding stopped about 2 hours later.
And do you think that she missed her period or that its just me being paranoid and that she might have it soon?

Finally does anyone know how long it takes o start feeling different or "pregnant"?
Please help me