Heyy. Some help please

I had sex on may 20 and took plan b may 21. My period ended on may 19. the thing is that on may 27 i had a brown discharge and sometimes red. It lasted till may 31. My period was supposed to come on june 14 but it didn't. On june 17 i had a pregnancy test and it came out negative. I don't now if i need to wait my period on june 27 because of the bleeding i had after plan b.