Personal question but really need (female) help!!!?

Okay. So here's the thing. I'm 14 and I had sex last week for the first time (I know I'm under age and everything but I was pressured into it). I had sex the day I was supposed to have my period but it didn't come so I figured it would be fine. He used a condom and I'm not on the pill. My period is now a week late and I'm freaking out! I don't want to be pregnant especially at this age. I'm so stressed out about this and on top of this my school semester is really hard so that's just adding on to the stress. Is it possible I am pregnant or could there be another reason my period is so late? Also even though I'm young, my period is very regular, it's never this late. Please help! Thank you!