Help! Brown spotting day or two before AF

Hi ladies!

Does anyone experience brown spotting/discharge a day or two before AF each month?

It definitely is not implantation bleeding as it occurs every month.

I have read online that it could in very few cases be a sign of low progesterone. However my luteal phase is the optimal length of 12-14 days for likely normal levels of progesterone.

I am looking to hear if anyone else experiences this too!!

Thank you!!!