BBT and Implantation

Hi Glow community! So I’ve gotten a weird temp chart going on. I’m wondering whether the dip I had in temperature 🤒 this morning could be from possible implantation? Or is it more likely AF is coming? Period is due in 5 days. I’m 8 dpo. What do you all think? (And yes I’m completely aware I haven’t been taken BBTs for a long time, hence I’m asking for all of your opinions. Thanks! 😊