can antibiotics affect your period

So I am taking antibiotics for my acne so I can clear it up quickly for prom(they're only temporary once I run out I'm not refilling the prescription) but my period is a week late and I would say that my period is fairly regular there are sometimes when it is early or a little late. But this is the latest it's ever been and I don't think I could be pregnant bc my boyfriend and I do have sex but we always use a condom and when we think it maybe break in the middle of sex we will stop and change it out just so we are careful. He doesn't always cum either. And from my knowledge the condom has never broken. So do you think there is any chance of me being pregnant or could it just be the antibiotics bc I read somewhere that it can affect your period but I wasn't sure if it was true. I'm going to get a pregnancy test tomorrow but I'm not sure if it's necessary. Also it could be stress too bc I had all my AP exams last week so I was stressing out about that. I just need someone's advice please. Thank you