BBT dip?

emily • me 38 :: DH 40 :: DS 2 :: TTC #2
hi ladies!! I'm 9DPO today and my temp dropped nearly to my coverline. I did wake up a little less than an hour early but my temps have never been so dramatic. I'm also feeling a little chilly this morning. AF isn't due for another 5-6 days. is there any truth to the "implantation dip?" thanks!!​