Help!!!

I'm 16: 
1. I usually have a 28-30 day cycle 
2. I had unprotected sex on the 14th day, which the app said was the highest fertility rate, 33%. He had a condom on the first time and about 30 minutes later we did it again. He kept pulling out just to be sure but I'm afraid something could've snuck in and I could be pregnant because of the high fertility percentage. 
3. I'm currently on cycle day 16. I did not take any plan B, and now it's almost too late. I should have ovulated already and I'm really scared. I couldn't sleep, I feel weird, I get slight hints of dizziness here and there. 
Is this all in my head? What should I do?