I usually ovulate on CD18 so I began testing early using my clear blue digital as well as wondfos as backup. On CD17 I got my solid smiley (peak) and some pretty good lines on my wondfo. Fastforward to today which is CD21 (I kept testing just in case) I got a really dark wondfo and a flashing smiley (high) on my clear blue. Can anyone with experience give me some insight on what might be going on?! The top picture is from CD17 and the bottom is today CD21