Really bad cramps

I'm 20. I've had my period since I was 12. And I have never experiences cramps nor back pain, nor nausea or headaches. I get my period poop once a month and that's it. Apart from feeling damp I have no crazy symptoms and I'm so thankful for that. But now here I am about 4 days after my period ended And 2 days after I had sex, I have really bad cramps. And When a cramp hits me, I have to bend over and crouch to help alleviate the pain. also I've been extremely gassy all day and felt very bloated around my mind section as well as a little lightheaded. Is it possible that I may start getting period pain symptoms? thoughts?