No Show Of Period 😯

Valeria
Okay, so I had unprotected sex last Thursday. My boyfriend finished inside of me. So the next day I went on to get a plan b prescription from my obgyn. She did explain that I would be getting my period as normal and the pill will not delay it. I took a test yesterday and it came out negative. Tomorrow is a whole week since I've had unprotected sex. Should I be concerned ? 
Help 😬