I had sex on 4/5, and my partner used condoms the first time and withdrawal the second time.  I took the Plan B pill the next day.  A week later (4/12), I started spotting and having a mucous-y discharge.  I had sex again that evening, once protected and once not (dumb, yes).   I calculated my normal high fertile days, and it appears that 4/9-4/13 would be the most likely times.  How much does Plan B affect normal ovulation?  I still have some random bleeding but wonder if the second time (4/12) could have caused pregnancy.