Quick question about ovulation

I feel a bit silly asking this.
Since Feb 15 I've been using ovulation tests, and suddenly there was fertile mucus on Feb 17. (that day was supposed to be my ovulation day). But the ovulation tests indicated that ovulation was nowhere near. Until today, when suddenly there was a positive ovulation test.
Now my question, if you have fertile mucus, doesn't that mean your ovulation is almost here or has just happened? (I read online that it could have just happened, not sure if that's actually the case). So is having ovulation 6 days later pretty late? Or am I completely wrong?