Implantation Dip or AF on her way?

[FigandHoney]

This morning my BBT took a nosedive.
I am expecting AF on Sunday. But normally my BBT drops more gradually.
The fact that my RHR is still high makes me cling on to hope, as that was what happened in my last pregnancy.
But is there any chance this is actually an implantation dip? Or am I just kidding myself

Forgot to attach my chart

@FigandHoney hi, sorry it can be both - implantation or just a change in hormones. I have them too on cycles I was negative, but on a positive ones actually very small and a few 🙈
Just get patience from somewhere and see how it goes next few days xx