Just so confused

I was on the depo shot from Nov 2018 to Feb 2019 & got off of it so me and my BF could start trying. I had finally had a period that was on and off for a little over a week, & actually ended up taking a plan B pill. Since then I have not got a period, except I had bled one day 9/13 and haven’t bled since. All my tests have been negative, but I’ve been getting really nauseous & having the CRAZIEST dreams which I’ve never been much of a dreamer before. My sense of smell has been crazy too. Could I be pregnant? If not, what else could it be?