I was suppose to have my menstral cycle on April 30th. That day has came and went. I took a home pregnancy test yesterday May 2nd and it came out negative. What should I do

I also was on the depo shot for 2 years. My last injection was June 2012. I am trying to get pregnant but I thought it took exactly a year for the shot to completely drain out of your body or sometimes longer. I have been on a regular cycle since I stopped the shot and to me have been ovulating every month... My obgyn said that there is nothing wrong with me and to just keep trying that it will happen. Is there a possibility that I am pregnant?