OPKs arrived yesterday. I had a EWCM 2 days ago so I took OPK test to see if i'd get a positive. i accidentally dipped too long 5sec so i did another one. First one looked neg and second one looked pos. naturally i did a third one and it was neg.
i thought opks would be more definitive and less guessing. I looked at few opk images on line and it seems it is up to the tester what darkness level they take as pos vs negative.
are all pos opk have same dark line as the control?