4 days before missed period... is it too soon?

Hello TTC Ladies,

Aug 10th is my next expected period and today Aug 6th i had taken a first response early pregnancy test and it came out negative. can i assume that i am not pregnant already?

I have observed 3 symtoms so far frequent urine(strongly recognizable), headache and backpains(on and off), and breast tenderness(very mild). Given these symtoms i was very hopeful to see a positive.

Can i completly trust these early pregnancy testers?

Thanks in advance.