TMI Implantation bleeding?

Implantation bleeding or start of AF? I never have spotting. My cycles are super irregular as I have PCOS, I’m on CD 48. I had VERY light pink spotting last evening and slight cramps. I thought for sure I’d wake up to AF today but no... only a few times today I’ve had light pink spotting, barely enough to see. Now tonight I have this... so confused

Also feel a fullness, no more cramping, but my back is slightly achey.