Clearblue Digital OPK's

I'm using Clearblue Advanced Digital opk's and for 3 cycles in a row, I went from "O" (not fertile to a solid smiley (peak fertility). I have yet to have a flashing smiley (high fertility). Anyone have this happen to them? I started reading more about this particular opk and the manufacturer says that they're "advanced because they measure both estrogen and lh surges". High fertility days appear as estrogen levels increase and peak fertility when you have an lh surge. I'm worried that because I never see a flashing smiley, that my estrogen levels must be off???