I Had Sex For The First Time On Saturday Night

I had sex for the first time on Saturday night using protection and there was a point where he entered me for a second without it. Then, monday night the same thing happened. Tuesday afternoon around 5:00pm I took postinor 2, 5:00 am respectively to the 12 hour rule... I'm suppose to have my period this Wednesday and today is Friday and it still didn't come.... Im worried that I might be pregnant... I need answers