Positive opk at 6dpo!

This morning I woke up and thought “screw it, let’s test using an opk.” I’m only 6 dpo but I’ve heard of women getting positive opk when they are pregnant. Not wanting to waste a pregnancy test I used my clearblue advanced opk with morning urine. I tested with an frer & opk 2 days ago (this 2ww is killing me clearly) & they were both negative. But today I got high fertility on my opk (flashing smiley!) so I decided to test using another frer pregnancy test but that came back negative. Is there any way my opk is more sensitive than the first response? Could this be a possible pregnancy indicator????