I noticed that when I work more, like doing some cleaning, washing more dishes, cooking, studying... I normally will have a pain in my back but also I notice that I would bleed down there. I would bleed little bit for like three days or four and it is not my period yet. My period will eventually come at its time or get delayed. Once I don't do those house work things, I am alright. Whenever I do lots of work, I got that. What possibly I am having? and is that normal? P.S: I am in 20's, and virgin.