How many days of EWCM is "normal"?

Hi everyone,
I'm 32 and TTC for 8 months now, but I've only been tracking "data" for the past 6 months. I'm realizing that my periods are not as regular as I thought (cycles vary from 22-28 days) and my fertile window changes and I'm sure I keep missing it!
I've started to keep close track of my CM. But I'm confused!
Should I assume that if I have EWCM that I'm in my fertile window?
And how many days of EWCM is normal? I'm on my 9th day. 
Glow always puts my fertile window when I don't have EWCM, so I'm not sure what to make of it. 
I haven't used ovulation kits yet. 
Any insight is appreciated :)