Blood in CM

Hi ladies, I feel like I am going insane wondering and so would like to hear your thoughts. Yesterday I was 9dpo in a 31 day cycle (AF is due 1 September) and I experienced spotting/staining in my underwear and dark brown CM when wiping. I still have brown CM today when I wipe but it is very sparse in comparison to yesterday. What do you think? Could this be implantation bleeding? I am doubting an implantation bleed would last this long?? Me and my hubby have been trying to conceive for 13 months and I have also been diagnosed with Polycystic ovaries. I know that irregular bleeding is a symptom of the condition, however this symptom is not something I usually experience. My periods are always spot on! 🤔

Has anyone else experienced this?