later period am i pregnant?!

i was on only on bc for a short time, from 22nd december till 11 january and me and my partner had unprotected sex the night of the 11th, he pulled out! but is there a change i could be pregnant, my periods is currently a few days late and i had dark brown discharge when i wiped for a couple days last week, i’m having cramps and scared i’m have pregnancy symptoms, please help and comment !!!!!