When do you get EWCM vs when do you get a positive opk? At the same time? Or does your cm come first and +opk later? Trying to figure out why I'm not getting +opks...

I've had EWCM for two days now but no + on my opk strips. I've been ttc for #2 for 7 months and at first I was just using an app and going by cm, but I think the app had me thinking my fertile period was later then it actually is. Just started opks for the last two cycles and haven't got a positive yet.