When i had unprotected sex i had only just started my next pack of bc. i had only taken 3 pills, so i took plan b. i then continued taking my birth control. all of that happened 2 weeks ago, and today i started having a discharge that it a yellow/brown co

Can do preg. test: 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. A continued, undesirable vaginal discharge means a trip to the doctor to check for sexually transmitted infections (STI's, STD's).