I get a four day period and it finished on the 24th of May.. 9 days later (the start of ovulation according to the calander) I had sex but the condom slipped off. I took plan b 12 hours later (2nd of June) and then I got brown discharge for three days a week later. I had one day blead a few days after that but I still havnt got my official period. It's now 36 days since the end of my last period (which come fairly regular). My question is is brown discharge a sign that plan b has worked ?