Help please

Jenny
I believe I O'd on the 4th, since I had EWCM, I tested today & I got a BFN :(. 
I have the urge to pee constantly as well as feeling like AF is going to show her ugly face anytime now but so far nothing. Have been feeling nauseous, headaches & sometimes I get the 'flu' feeling. If I was pregnant, wouldnt I be getting a BFP by now? Tested with a blue dye family dollar test.