Pregnancy Scare? (Or Paranoid?)

Kalea
I'm probably just freaking myself out, but I thought I'd get some opinions from you lovely ladies.
So, I had sex back in March, apparently. I was black out drunk but told the people who found my dumb drunk ass that I did. 
I don't see why I would lie about that, so after sobering up and dealing with a lotta consequences, I started to freak a bit because it was during my fertile week and I have no clue if the guy used a condom. 
Now, my period came that month, sorta. It seemed more like heavy spotting for like two days then stopped. 
My period is normally super heavy and lasts for a week. 
I took a test and it came back negative. So okay. I calmed down for a bit.
But I've been having more mood swings than usual and they're different from my normal ones. I've been having bizarre cravings and I've been having some cramping in my lower abdomen and I've been sick to my stomach. 
My period is due to start next week, so I'll see how that goes, and take another test if it's weird.
But what do you guys think? Does it sound possible or and I just overreacting?