I thought I might share this with those who are testing with their OPKs. I started testing again on the 15th, CD21 after a series of no positives on my clearblue digital Ovulation test. I've been testing with two kits, a cheap generic one and the Clearblue. I got positives on both kits and a smiley on the clearblue on the 15th. Out of curiosity, I tested again on the 16th on the cheap ones since I had quite a few dozen left over. It still gave me two dark lines, positive. Never mind. Then today, 17th I tested again, and STILL got two dark lines. Really crazy, I can't believe my LH can stay that high. Then I tested again with my Clearblue Smileys and thankfully, I did not get any smileys at all today - meaning I AM COMPLETELY Normal, hormones are normal and I can't be ovulating over so many days...... For those of you who keep getting positives and lines on your OPKs and don't understand why, maybe get a better one like Clearblue.