Would I be Pregnant??

Hello gals,

I got off Depo back in December 2016 and in March got my period. Then in April & May i got nothing same as in this month nothing no period, I even check on a pee stick it says I'm not pregnant maybe i check too soon or I don't know! I have back pain like crazy when i sit too long as well as standing...I feel sick once in awhile but won't barf, I'm mainly so tired and i can't fit in my jeans my stomach wants to be out. I touch my stomach its a bit hard also get cramps too. I don't know what to do...can anyone help me please!