I had sex the day after my period and took plan b 7 hours later. 5 days later i start bleeding heavily for 3 days only and another 5 days later i noti?

About Plan B...: Taking Plan B can alter the timing and quality of the current menstrual cycle and the next upcoming cycle. One should check a urine pregnancy test 3 weeks after taking Plan B, because Plan B works most of the time but not all of the time. Home urine pregnancy tests are very accurate, and are sold everywhere at a low price. If the amount of vaginal bleeding is worrisome, one's doctor can evaluate.