So I've been using the clearblue advanced OPK with the blinking and solid smiles. The first month it worked just like the box said - 2 days of blinking smiles for "high" fertility and then the solid for "peak". This month I'm going on my FIFTH day of blinking smiles. Has anyone else had this issue before? I'm testing in the morning like it says to on the box and hoping I haven't missed it.