I got off depo in march if this year my first period was oct 10 2012 my next period is 12 days late.

I was depo for abt a yr n 5 months I got off the depo shot in march 2012 that's whn I got my last injection after may I did not have a period for 6 months I got my first period oct 10,2012 it lasted 5 days which is normal for me cuz my periods are normally 5 days after my period I had sex with my boyfriend I keep track of it on my period calendar my next period was due nov 7 me n my boy had sex the day my period was suspose to start but I did not have any symptoms of my period coming on it's been 12days n my period has not came I been eating alot I been tired I have back pain n sometimes a sharp pain on the side of my stomach my stomach pokes out a lil bit I'm small I'm 4'10 n I weigh 111 I have lost 12lbs within the last two months I was 124 I feel bloated n I sometimes walk funny cause I'm in pain I took a pregnancy test n it came back negative but my stomach is still poken out lyk I'm full but I haven't ate anything.. I'm confused if I'm nt pregnant then why am I having all these symptoms? Is this side effects from the depo? I'm also afraid that I can't get pregnant because of the depo n how it affected my body.. Plz no negative comments