Pregnant or tricking my mind?

I had sex with my guy friend and I was SO worried about being pregnant after that, I was EXTREMELY STRESSED OUT...and then after 10 or so days my AF came, it was 6 days long and heavy as usual. AF ended a week ago and I felt randomly dizzy and kind of nauseous, and I'm starting to think every little thing is a pregnancy symptom (like my stomach is tingling, nipples feel like their Perkier or tingling)....I also took 2 tests before and 3 after AF and all were negative. Still isn't giving me the pieces of mind I need so do you think I'm pregnant?