is it to soon to test for pregnancy?

So about 3 weeks ago i had unprotected sex with this guy about 3 times within an hour and i wasn't to sire if he pulled out or not because it didn't seem like it. But lately ive been nauseous all the time but haven't been throwing up and ive been super hungry and alllll I seem to do is sleep. I hope its just paranoia but are those usually signs of pregnancy or am i just tripping? Also my period was supposed to start yesterday but it didn't but i have been feeling little pains down there that don't exactly feel lilke my normal period cramps.  Should i wait a week and test or am i just paranoid of the way ive been feeling?