Late periods!!!!

Idk if its just me, but im 15 and sexually active and im super safe about everything i do. Ive never fully done it without a condom but i my bf has put it inside of me without one before but only to see how it felt. I always use condoms, but i still freak out when im a few days late. My period comes on different days every month. Usually at the beginning of the month. I havent gotten it yet and im stressing myself out...rn im 3 days late from when i got it last month. Is stressing out making it come later?