Could I be pregnant?

I have sex with my boyfriend a lot and each time we do it he pulls out just before he cums. This is every time no fail! But I'm 5 days late and although my periods don't often be on time this is the longest yet I've been late, and of course the stress of thinking I'm pregnant doesn't exactly help with it coming. I've also just started uni and live with other girls and I've heard this can take a toll on a girls period too! Anyway if someone could add in a bit of advice that might help that would be great 😊