could i be pregnant ?

my last period was December 11-18 and i haven't had sex after i've been off of it. i had sex sometime before i started but it was after the 2nd. could i be pregnant? please don't tell me i'm dumb. i've been feeling nauseous and i've been gassy. i've also been have trouble sleeping and i've had diarrhea. however, my grandfather just passed away so i'm not sure if it's caused by stress. i know i need to take a test but i can't rn so do you think i am? i've always had protected sexy and i'm supposed to start my period in 10 days. i've never felt nauseous before my period but the other symptoms are pretty much the same