"i had sex on the last day of my period, then i took plan b 11 hours after i had sex. a week after taking the pill i experienced brown discharge which was heavy like a regular period the first 2 days then turned into spotting for the next 3 days. my regular period usually lasts 5 days so i figured the pill just made me have a fake period to trick my body into getting rid of the egg before it got fertilized. i have a period app on my iphone that tells me when my period is going to come and tells me how many days i have between cycles for me, it&#039;s 28 days. so i counted 28 days from my last day of brown discharge and the date my period should have come was the 29th of october and it did!! i hope this helps someone out there!"