Possibly pregnant??

So i may just be panicking but I figured you all have better knowledge than me. I'm 15 and my mother doesn't know I'm sexually active. Yesterday I had unprotected sex with my bf. Pull out method. Horible decision. Anyway my <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> always gets my period right. And its not here. I have no clue what to do. Every once and a while my period will skip due to stress. I was quite stressed all last night. (Lost pet whole other story) Help!