I discarded it bc I didn't think it would make a difference bc it was the same as the day before and it gave me chs for cd16 but then if I out the temp back in it took the chs away so I figured it needed to be in that day to be accurate but even with it in and temp in today it's giving me dotted chs so now I don't know what to think lol I bd'd last on July 24th which was cd14.