disappointed...Bfn 5 days b4 af

I realize it was a long shot that after only having sex once during my fertile week I'd get pregnant but it just felt so different this time. I had been experiencing cramps post ovulation and slight nausea and I even had two days where I found very light pink traces of blood which NEVER happens to me so I thought it could be implantation. I guess it was all in my head because this morning I tested using a first response test and got a negative.