Can plan B mess up my period???

So I took a plan b pill on May 30th about an hour after a condom break disaster. The <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">Eve</a> app told me my period was supposed to be June 13th-17th. I had what seemed like my "period" throughout those days, heavy with severe cramps on the first few days and light towards the end, except it was brown and more of the consistency of discharge, is this normal???