Interesting! I thought about getting the Ovacue but ended up getting the OvWatch, which I think detected ovulation by testing the chloride levels on your skin. Angela, I'll go look up the info on that one if you are interested but I'm feeling lazy.

It's something to do with your electrolyte levels changing a few days before you ovulate. My OvWatch was pretty accurate, it either got when I Oed exactly or was one day off. I stopped using it though because I got better at predicting O without it and because my problem getting pregnant wasn't related to bad BD timing.