How to properly check CM? TMI

Bronwyn • 31, firefighter and peace officer, married 2 years but together 14. Our first baby!
Hey ladies,
​I have an odd question I guess. What method do you use to check CM?  I find unless it is obvious on undies I have to check by inserting a finger.  Do you base it off of the deeper fluid or just what is found on your undies?  
​For example. Today I thought 'dry' because nothing seen.  Inserted finger and thought 'watery' but when I checked deeper it was definitely 'creamy'.  Thanks and sorry for TMI. Want to make sure I'm tracking right.