4 days late and BFN

I'm so confused as to what's going on. AF is always on time (28 day cycle) and here I am on cycle day 32, light cramping and no AF. I had some I guess you could call spotting the last 3 days but, only 1-2 times each day. Yesterday morning it was a pinkish color when I wiped and last night a brownish color. And today just a pinkish color. I don't get what's going on. Clearly a negative test so, I am even more confused.