I have been getting depo shots for 7 months. I hadn't had my period in 4 months then last month I had it again right before my shot. I have been super moody and nauses. Could I be pregnant?

Any time you have sex, even if you're using protection, pregnancy is possible. So yes, you could be pregnant. You take that risk every time you have sex, even on Depo.

Depo works differently in different people. Some can go four months between shots and never get a period, and other will go three months and have one before their shot.

I think you should explore other birth control options. This might be effictive for you.