Am i pregnant or just paranoid?

I had sex about a month ago, and i was supposed to start my period about a little over a week ago but i didn't. I dint really think anything about it cause Ive been extremely stressed for the passed month and I've herd that can cause you to miss your period. Then today i started me period, or at least thought i did, and a couple of hours later i started getting really bad cramps to the point i couldn't stand up straight. I don't normally get crams, Ive gotten them once or twice been they weren't bad at all and i didn't know if they were just normal cramps and im just paranoid and am not used to them or if somethings wrong