3 weeks ago i had sex, we used a condom but it broke so i took a plan b pill a hour and half later. since last week ive been having light bleeding per?

It happens sometimes: Plan B can alter the menstrual bleeding for the cycle in which Plan B was taken, and sometimes the next cycle too. One should be sure to check a home pregnancy test about 3 weeks after sex, because Plan B works most of the time, but not all the time. Tests are sold everywhere, and are cheap to buy.

Normal: It was wise of you to use plan B. Plan B works by disrupting the normal menstrual cycle, so it is quite common to have abnormal bleeding after using it. This should return to normal by itself. Remember that plan B does not protect against sexually transmited infections, so you may want to be tested for those