Period or implant bleeding?

So I'm almost 1yr postpartum. Hubs and I don't dtd much right now. The last time we did was Aug 8th. I have not started a period yet but today I started getting pink tinged.ewcm type consistency mucus. 3+ weeks after dtd is way too consider pregnancy right? Is this return of fertility? Something else? Can you tell based on my chart? Thanks. I'm 36 if that matters.