What Causes Delayed Menstruation Despite Provera Intake?

I've been off of depo provera shot since May 3rd. I was on the shot almost a year. I haven't bled or anything since ive been off. I've even taken the provera hormone pill and I still havent had anything happen. These past couple of weeks I've been having cravings, sore nipples, lots of egg white discharge, mood swings and urinating alot lately. Ive Also been really thirsty. Ive taken a test and its negative. Is it my period coming or could I be pregnant? Me and my husband and really trying for a baby so advice would be greatly appreciated.