Very very light spotting every month 7-9 dpo?

Megan

Prior to having a miscarriage in October I never, ever noticed spotting prior to my period. Since the miscarriage, each month on 7, 8, or 9 dpo one time during the day when I wipe after peeing there’s a couple light pink spots on the toilet paper. The first time it happened I was excited thinking it was implantation bleeding, but now that it’s happened three months in a row I know that it’s not. Could this be a sign of an issue such as low progesterone or something else? Anyone else experience this?