Hmm, I wouldn't say it's completely impossible if the test was a little defective at detecting it at the right time. I've read that women always have some sort of line on a opk after they ovulate. So if your using it as a hpt, be careful. (for some it has worked because the line was super dark on the opk. but I don't recommend it lol)
Thank you. I actually have the one with the smiley face. But for some reason it was positive earlier than normal. I stopped after that so don't know if it were a defective one. It was odd but then again my cycle is crazy so who knows. I never used it as an hpt though. I do have quite a few and today had a bfn. :( guess ill have to move on to next month. This time ill continue my opks for a few extra days to see what happens