First (proper) cycle on progesterone

This is my first full cycle taking progesterone from after confirmed ovulation . Forgive me if my query is ... ignorant. I’m new to this.

I’m on cycle day 26, and I’m 13 DPO. I noticed pink when I wiped last night and this morning. Is my period trying to breakthrough? I don’t think I’m pregnant, I tested a stark white bfn on 12 DPO.

But if my period is trying to start, does that mean I should stop the progesterone early? I was planning to use my last one on Monday , per doctors orders.

Doctors office is closed so I can’t report the link when wiping. Thoughts?