Too eager to wait

So on July 4th I was ovulating. I had sex that night. On Monday July 11th, I had this light pink bleeding. Several people said that the light pink bleeding looked like implantation bleeding. I'm supposed to get my period on the 19th.
Today I took the cheap Walmart First Signal test, and it was negative. I really hate's only 3 days until I should get myperiod, but this waiting sucks. Is it normal to have a negative test 3 days before a missed period? I'm hoping to miss mine in 3 days.