When does ewcm occur?

Anissa • one gorgous doll baby in 2015 😍 one miscarriage at 7 weeks March 2018 😔TTC baby #2! 🌈
So I saw a bit of ewcm this morning, but as usual, it's not a huge amount. I have been using opk's this month, and they said I have not ovulated yet (and they aren't coming back with dark test line results). Could this be a sign that I'm going to be ovulating soon? How soon before ovulating do you all notice ewcm?