Clearblue Advanced OPK advice for you!

Jema
If you're using this brand of OPK's, don't make the mistake of only testing once in the morning! I did that for two cycles and never saw a "peak". Today I tested in the morning, no peak... just that damn flashing smiley. Then I tested again at 3 pm and got my first ever solid smiley "peak". 
I was so worried I wasn't ovulating!
Just remember not to drink much during the day between tests. 
Any similar stories??