Anyone else??

So I’m like 14/15 DPO. And I’ve had off-and-on spotting for the past week. It’s super light & pinkish/brownish looking (it alternates). AF is normally very heavy with lots of clots & I never spot beforehand. Also, very irregular due to the PCOS. I’ve been having very light cramping (which I never have with AF), lower back pain, nausea, and tender/sore breasts. Took a test yesterday morning & it was negative. Did anyone else get a late BFP?? Or should I just assume this is AF?