Suggest Treatment For A Delayed Menstrual Period

I was suppose to go my Obgyn to take my Depo Injection on June 9,2014 I did not go take it,I started my period on June 19,2014 I had unprotected sex at times during those days of my period, my period lasted 15 days which was until July 3,2014 my period went off July 4,2014 it came back on for a couple hours it was light pinkish-red on July 12,2014 I done a home pregnancy test it was negative. Today is July 19,2014 I have not started my period what should I do please give some advice?