Why The Periods Are Missing?

So me and my boyfriend decided to try to have sex, for about 5 min and decided since we didnt have a condom we didnt want to risk it. I know of this pre *** thing but can it make you pregnant? My periods way late, but it was late before me and Him even had sex, We fulled around earlier that day.We didnt have sex at that time but he did *** and it wasnt till a few hours later we tryed to have sex, What are the chances of my getting pregnant from Pre ***???