Depo shot question? Pregnant or?

I got my first depo shot about the end of december/begining of jan. I got the 2nd one sometime in march. I was due for my next shot in the begining of june but decided not to get it. The whole time while i was on the shot i still had my period regularly about every 28 days although they were a little lighter and lasted longer but i nevet missed one. I had my period in the begining of july and then two weeks later at the end of july. I missed my period my period for august and september and have been having cramping on and off since the week of my first missed period. Is this normal after getting off the shot? I have had unprotected intercourse but i took a hpt and it was negative so now im clueless. Oh&& i've also been having more clear/white discharge&& have been very bloated. Help?