Sonya - (TMI warnig)
I have to check internally, as I dont get any externally to check... (remeber to wash hands before)
I check every time I go to the loo when i think O is approaching...
And I look for my cervix, and get a bit from there...
I only check cp once a day though, at the same time every day, but with CM just go with the most fertile you observe in the day.
HTH
xo