Fertile CM can also be achieved by having triple the dose of evening primrose oil capsules. I tried it mid last year and it worked on the first cycle I used it on (resulted in m/c). With this one I just saw one blob of it the day before O (didn't use EPO) and here I am at 16 weeks so you could have it and not even notice it. If your CM pattern is different to normal at CD21 it could be a good sign. I hope so.