Last mens: May 13, 2015

So here's what happened, I had sex with my bf on the 11th, Glow says I am going to have my period on the 15th but it came 4 days earlier. My period came the day after I had sex (withdrawal method)

Is it possible that I am pregnant? Please help me!!

Btw, my period this month is vert unusual because I normally have really severe cramps & my flow is heavy during my first day but in this period, I never felt any pain or even PMS like before..

Is it possible that I am pregnant? Please do help me..