Of course you can get pregnant. I suggest you use a home pregnancy test as a preliminary measure If it's positive, consult your gynecologist regarding options available to you, including RU486 if you don't wish to continue pregnancy at this time.
Here's information about Depo from the official site:
"Women who want to become pregnant may stop using Depo Provera at any time. For some women, fertility returns immediately. For others, it may take 6-18 months or longer for the body's hormone cycle to go back to normal."
For further information, I suggest you post in the gynecology expert forum at: