my symptoms - do you think i am pregnant?

i've had unprotected sex 3 times this month, and my last period started july 25th. i was supposed to get my period today but i didn't. i've been having stomach cramps for a few days, dizzy-ness, nausea, heartburn, shortness of breath, tired all the time, super sore breasts/nipples, and what i think was spotting. i'm not sure and i'm terrified. what's your opinion? & i'm taking a test tomorrow but i just..want to know whether i should get one or not