Am i pregnant?

Me and my boyfriend have unprotected sex on a regular basis. He always pulls out. I have the nuvaring in me and I'm pretty sure I'm using right? But, yesterday I was supposed to get my period and nothing, I didn't even notice(since my period is also irregular sometimes) until today I got cramps but no period. Am I pregnant or am I just freaking out?! I don't feel tenderness in my breast and I noticed my back did hurt when I woke up but I thought that was normal.