just in time for Christmas?

I stopped taking the Depot shot in August (didn't get the one due after the one on may) because my boyfriend and I are trying and had my first period in November. It was a pretty regular period and lasted 6 days.  I was due to start again 3 days ago and have no period in sight. Took a test Saturday morning and it was negative. I've been feeling emotional and very gassy lately and my hunger pains in the am are extreme to the point where if I don't eat fast enough after the pain starts, I get nauseous....anyone have an opinion on if I might be pregnant?