possitive opk using fmu?

[kirstr1984]

So I'm cd 35. Have very light brown spotting. I thought I was pregnant but negative test. I have ewcm so took a opk this morning
Bam it was clearly possitive. Any ideas?

 

[purplecupcake]

Most OPKs tell you to test in the afternoon, firstly because FMU will usually have higher concentration of LH whether you had your sure or not, thus leading to false positives. Secondly, your LH surge usually happens overnight in the early hours of the morning and needs a few hours to show in your urine. Since you're having EWCM now, it's possible you are catching a surge from yesterday.