Am I pregnant?

I started my last period July 9th and it ended on the 13th. I had unprotected sex on the 13th and the day after I used birth control pills as EC (I havent been on it in like 2 months and had some leftover) A few days after THAT I had some brown discharge. (Which i assumed was from the birth control pills I took)

So, what are the chances that I’m pregnant? My period is supposed to come tomorrow but I havent had any symptoms. Should I be worried?