Pregnant or No

Hi I'm on Depo Provera, but I just got my shot 2 weeks ago BUT I got it late because I couldn't remember to go to the doctor. But I did have sex during that week of No Depo. And I've been having headaches and gagging to weird things like today I had baked spaghetti and to think of it makes me gag and I threw up after eating it. I do feel nauseated sometimes since then. Plus I just been having weird pregnancy symptoms. So could this be baby #3 or I'm overreacting ? I do remember two of my friends getting pregnant and they were on Depo Provera. (Also I got my shot two weeks late and had sex more than once )