EWCM: anyone like me not have it, then do something to create it?

Melissa A • DS 4/6/06. DD rainbow 10/19/15. Pregnant w/ #3 due 10/3/18
I have only had EWCM once. Is anyone in my shoes? Has anyone not had it, then taken supplements or changed diet, and then gotten it? I tried primrose oil for two months with no results. I've tried eating foods that are supposed to encourage it, and nothing. We're using Preseed but EWCM is in your cervix so Id really like to have it if possible!