What is going on?

I got my first dose of depo in April and then got my second dose a few months after that and was supposed to get my other dose sometime between 9/20-10/4 I had sex 10/15. I tested and got a clear negative. I haven’t had my period since April because of the depo shot. It is possible to be pregnant or maybe my period is coming I have been a little nauseous, just feel spacey like dizzy off and on. We had steak for dinner and I had to reheat it because it was to rare and usually I like my steak rare and then today I had a fish taco and took a few bites it didn’t take good and threw the rest out. Could it be my period starting or maybe I’m getting sick?