11% chance of pregnancy?

So I’m 46 days late for my period, and I am quite irregular anyway, so it isn’t really anything too out of the ordinary. Anyway I had sex a few weeks ago but we used a condom, and he actually pulled out without cumming at all, so it’s quite literally impossible that I’m pregnant, right? I haven’t had sex since and was supposed to come on my period 46 days ago. This is baring in mind that I’m a 17 year old girl sitting almost 20 exams at the moment. I just need some reassurance please ladies, I’m pretty sure I can’t be pregnant but can you all let me know your thoughts? Stress or not?