No period yet

I was supposed to start my period on the 11th, had protected sex on the 4th and 10th. I still haven't started it. I took a test and got a negative. I also just ended my basketball season, I have been told that it could be delayed because im not active everyday and im not around the same girls much anymore and our cycles were synced up. What should i do? I dont know what to think and my boyfriend and I have been freaking out!!!!