What Causes Spotting After A Non Penetrative Sex?

Hi...I`m from Belgrade...and i have one question for you ....me and my girlfriend were fooling around...and i put my fingers on her vagina and for some time was rubbed her vagina...and over some time she had her maximum...but i didn`t put my finger in it ...but when she`s gone home she found blood ...and next day also ...can that be her period ?...is she still a virgin ?