I have had EWCM about a week after O before, these past few cycles it has been Creamy CM at that time. I believe it is caused by the rising estrogen levels at that point in the luteal phase. Does your temp also seem to dip on those days ? Mine tends to, I usually have a dip around 7dpo (check my chart in sig, you will see). I remember examining the TCOYF color coded hormone chart and seeing that estrogen does go up kinda high in the mid LP.
I have heard that pregnant women often get fertile CM in the 2ww
On a related note I was doing some FF research on implantation dip last cycle
and it says that 2/3 of the charts who show these temp dips are pg, 1/3 are not. They say that the dip might be caused by a secondary surge of estrogen that may occur mid LP. And they say that estrogen is higher in conception cycles than ovulatory ones. They also say the dip could be the effect of an implantation reviving the corpus luteum just as it starts fading out.
So, long story short I think it could be caused by estrogen and that it is normal.