April: started on 6th ended on the 9th
Took plan B on the 22nd
Started period again on April 29th, ended on May 2nd.
Started period again on May 13th, ended on May 16th.
And started again today on May 29th.
I've been intimate 8 times since I took the plan B on April 22nd.
Should I be concerned? What are some reasons as to why this has been occurring?