I m currently taking seasonique, a three month form of oral birth control. A week and a half ago I had sex, only to go to the bathroom afterwords and find out I had started my period. I m no where near when I should be on my period again, I m still on the first month of my current birth control pack. This period is unusual as well- in addition to the typical bright fresh blood , I ve been getting a lot of black chunks in it- it s what it mainly consists of. I m now on my 11th day of this, when my periods normally never go past 7 days. What s going on?