CM confusion

Hi everyone! I’m new to TTC after being on continuous birth control for ten years due to endometriosis. I’m trying to “get to know” my CM patterns because I’ve never noticed any changes. I’m confused by the “dry” CM. I’m never leaky, but I’m never dry if I actually go inside. Does dry mean you aren’t discharging into your underwear? If I don’t have discharge ever, am I always dry? Thanks. Also, anyone with endo can weigh in on that aspect, too! Thanks.