Is it normal to think that i am pregnant?

my boyfriend and i had sex on the twenty fifth of march. he was not wearing a condom, but it was more of an 'attempt' rather than actual sex. this was our first time unprotected, but we have had sex before. i'm not sure if there was any precum or not as there was some foreplay and oral prior. i was supposed to get my period around the thirteenth of april and still have not. could i be pregnant?