Can't see cervical fluid?

So I know you can check internally, but initially I was told to use toilet paper and wipe and note the fluid from there. There's nothing ever on the tissue that I can see. I can feel, but it's nothing I can really feel between my fingers. I have lots on my underwear, but isn't it hard to tell once it's dried up? Silly questions. I'm just trying to follow cm more this month.