pls help

so i had unprotected sex on dec 23, a day after my period just ended. it was only unprotected for a about 2 minutes then we put a condom on. i made him wipe before we had sex. it is now january 20 and still no period but many cramps?? i’ve had irregular periods my whole life and i’m just a bit nervous. i need some real advice i know i should take a test but i’m just too scared