Originally Posted by
atomic sagebrush
There's no such thing as an implantation dip. What people call an "implantation dip" is the temp dip from the secondary estrogen surge. It has nothing to do with implantation and the idea has been debunked.
Interestingly, they have studied this and have found that charts with a noticeable temp dip at aobut 7 DPO are slightly more likely to end up in pregnancy (I can't remember how much more, it's a small but statistically important % though). But it's not because implantation causes this temp dip, it is because, like we are just talking about, cycles where a person has a lot of hormones in their body seem to be affiliated with more successful conceptions. So the progesterone rise is higher, the estrogen dip is lower, and the two combine to make it really obvious that a big bunch of estrogen was released. Some women even have EWCM that day (I almost always do!)
Sorry, this is hard to explain in any language, please ask if something is less than clear.