Help!!

Charley
Okay so the last time me and my boyfriend had sex was on the 6th of September which was when I was ovulating and before then the last time we did it was on the 2nd. I took a pregnancy test last night and it was negative and so was the one from this morning. I've been feeling nauseous and having dizzy spells and my period is late. Is it too early for me to take a test? 
Basically what I'm asking is if I should trust that it's negative or if it's too soon to tell and I should wait a few more weeks and take another one. 
PLEASE HELP LADIES!!!