Sex pushing my Period back?

Lexie
Hey Guys! Just a quick question.
I'm pretty sure I was supposed to start my period today because I had some of that brown stuff yesterday in my underwear. Regardless, I had sex last night. 
I read somewhere that sex pushes periods back a little? How long should I expect it to be pushed back... one to two days?
Thanks! 
Sorta stressing 🙃