Pregnancy scare

I had sex on November 2, the night my period ended.. He wore a condom(only form of birth control) but I remember that he did not ejaculate(there is always pre-cum) he said the condom was loose so he changed it, I was supposed to start my period yesterday(24) (according) to this app but it never came, so when I added that I was late to my log it moved my projected start date to the 26, could I be pregnant or am I just stressing myself out