Late implantation?

Allie

I didn’t track ovulation this month I’m just going off of what Glow. If I were to have ovulated on the 27th —> could I have implantation bleeding today? (12 days later)

This morning when I wiped I had light brown/pink on the TP. Thinking I was going to start I put a pad on. There’s been nothing the rest of the day? I’m supposed to start tomorrow... do you think it’s AF or implantation bleeding??