Pinkish/brown spotting?

Ok so I normally spot brownish/creamy (TMI I know) 1-2 days before af. I was expecting af on Saturday 10/7 which would be cd26, I typically run 26-28 last 2 weeks 26 days. So starting Friday I noticed verrrrry light pinkish when I wiped, so light that you would have to really be paying attention to notice it. Since then it has gone from very light pink to a light brown/pink but is thin and watery, nothing thick or lotion-y like usual. I’ve been feeling like af is coming and then go to the bathroom and nothing? I’ve had cramps since Friday and continue to wake up with headaches and have nausea through the day in waves . Anyone have any insight? Took a test this morning and it was negative. This happen to anyone and then get a bfp?