So this is my second month using Opk's and I am a little confused. Last months results were perfect. Everyday my lines on my opk would get a little darker until I got a blazing positive when I ovulated. This month my lines would get a little darker, then they would be just barely there then the next day it would be *almost* positive and then my next test would be barely there. What does that mean? I know I am not missing my surge because I test twice a day. Any thoughts?