Could i be pregnant? even on the depo shot?

[shortstuff99]

So I wasn't on birth control and got pregnant in January of this year. Before finding out I was sleeping alot, my back was killing me, and I felt weak and nauseated. March of this year I lost my baby.

I got on the depo shot 3 months ago and for about 2 weeks after I was off and on bleeding. It was a brown blood though which was strange. I havent had my period since. Me and my boyfriend don't use condoms and he never "pulls out." For a few weeks now my back has been killing me and I'm tired 24/7. I sleep all through out my days. My attitude is on 1000. I've been feeling on and off nauseous, and today I got this servere migraine that still has yet to go away. Not to mention I'm gaining weight and my stomach is hard. I just want to throw myself away.

PLEASE HELP! And GIVE ANY ADVICE POSSIBLE!!!!