I Took The Plan B After Pill In September 26

I took the plan B after pill in September 26 2016, my period was not due until October 16 I was having irregular periods before the pill. But with the pill I received my period on October 1st cutting my period down to 26days that 1st period lasted 4 days (from October 4- 7) I received my second period 11days after So on October 15 my second period started lasting 4days again (period ended on Oct. 18). My 3rd period came on November 1st lasting 6days now that period lasted like my regular periods. Yesterday I had sex (11.16.16.) and after a while I went to the bathroom and notices some spotting light spotting. by the evening nothing was showing. Today (11.17.16) I had sex again in the morning no spotting right after but in the afternoon around 4PM I go to the bathroom and notice some spotting again... I currently have not been protecting my self meaning my partner and I want to conceive so there has been penetration.. what I'm worried is about the spotting and my irregular early periods???