I've been using the ClearBlue Easy Digital OPKs. This month I've had the flashing smiley (high fertility - estrogen surge) for the last 3.5 days. Tonight (end of 4th day of this), the digital display shows a static smiley (peak fertility- LH surge), BUT when I pulled out the stick it did not have the typical 2 lines, but that smear you see in the pic. Now I'm wondering if there is something wrong and if I can trust the digital reading of the LH surge. Any ideas? (Grasping at straws, but I did have a very strong coffee this afternoon, which I never have. ?)