I'm Was on the depo shot I took mu first one in the beginning of February I missed the next one I was supposed to get I was having unprotected sex a lot I got my period in June or July for about 2 to three weeks it was on and off I was still having sex times I didn't have my period I went and got the shot August 18 and haven't got it again since then I haven't got my period since July I'm having lower stomach pains and lower back pain feeling a little nausea I took a couple pregnancy test and they all come up negative could I be pregnant and not know