Thanks for writing to us with your health concern.
See, the ovulation predictor kit
is not always 100 % reliable.
Also, the discharge increases AFTER ovulation.
It is at its peak just before your period is due.
That could be one reason you got a negative test.
You had ALREADY ovulated.
However, you are still in the clear since you were sexually active during the requisite time.
Being sexually active well past your expected ovulatory dates will also increase chances of pregnancy
Another possibility is conditions like PCOD
which are keeping you from normal ovulation