The last day of my last period was August 11. I am on birth control and almost always remember, but I forgot to take it August 17th. August 18, had unprotected sex. 11 hours later, I realized my mistake, took that night's pill as well as the missed pill, and also took Plan B. I didn't have too many symptoms, but for a week and a half, I had very dark discharge. This happened when I should have gotten my period as well, and did not get my period. What sort of likelihood am I looking at here?