Ok so, my period started on Veterans Day, which was last Wednesday. And ended Saturday night/Sunday morning. So way too short. Plus, the last day of my period, I noticed the little amount of blood that was on my tampon what thick, and black. Any ideas to what's going on? I have been sexually active and have been using withdraw method only. I'm not on birth control, and I can't really just go to a doctor. My periods are normally about 6 days long. Any opinions would be fantastic!! :)