EWCM followed by non fertile CM! Help pls!

Megan

Yesterday I had what I thought was some Eggwhite Cm but when I checked later in the day it was kind of chunky... so not fertile.

Does this mean that I wasn’t actually fertile yesterday?

Or is having EWCM just once in the day mean your ovulating?

I just started charting today, so I can’t verify with temps.

Thanks!!