Continuous Flashing Smiley Face OPK

[Mezza610]

Hi
just wondering if anyone else has experienced the same
We have been TTC (trying to conceive) since May and have had AF arrive on time each cycle
I usually test with the Pink clear blue ovulation tests and always get a solid smiley faces on CD12 & CD13
For the past two cycles i've tried the Purple Advance clearblue tests....the first cycle i got 2 days of flashing smiley faces then a static on CD12.
However this cycle its been continuously a static smiley face and i am on CD18. Ive been using FMU everyday
Could i have missed my LH surge?

TIA (thanks in advance)

You might have missed it. I tested with my last clear blue stick this cycle at 7.00am it was still flashing. My Internet cheapy was positive at 4.30 by the time I got some new CB sticks (used same holder) at 8.30 it was just flashing again. So if I'd not used my cheaper ones I'd have missed it this cycle x