Hi Rachael,
I have the kind of spotting you describe when I am pregnant, early on about 5 to 6 weeks. The brown stuff is old the blood, the pink stuff is newer.
How late is AF?
HPT don't work for me early on!! My last preg was diagnosed with a blood test and HPT still came up negative after +ve blood test.
Could you be preg? Can you get it checked out?
BEST OF LUCK.
TICKLISH.