Late period /stressing hard

Allyssa
So I need some help, or need to know if anyone else has ever had my problem. So here it is... well a week ago I had an accidentally needle sick at work. (I'm a housekeeper at a hotel) well I went to doctors and they gave me anti-viral meds to make sure I didn't pick nothing up. They make me really nauseous and i always have to puke. Well fast forward a week and now my period is late, I'm over here stressing cuz I'm always on time and me and my bf had sex 2 weeks ago, but I have an iud, so I guess my real question is do you think my period is late because of the meds or because I'm stressing out over it. has anyone else had an experience like mine? I'd appreciate all answers and all comments thank you