I took plan b, 2 days later white clear discharge then brown discharge,a day after that had my period heavy for 2 days then light the next 2days preg?

Plan B: Plan B works by disrupting the lining of the uterus so a fertilized egg can't implant there. It sounds like it did what it was supposed to do so it is unlikely you are pregnant. When in doubt, take a pregnant test in several weeks.

Unlikely: Plan B is a reliable method of pregnancy prevention. In 2 weeks after you had unprotected intercourse do a home pregnancy test to be sure it is negative.