OPK Test Lines

Jessica • 34 : Married : 14Jun2019 👧🏻 : Hoping for 2nd pregnancy, Aug 2020

Can anyone tell me if the test lines can get lighter before it gets darker? I ovulated on day 19 with my first child so I started testing on day 17 this cycle, assuming I would ovulate late again, and my lines seem to be getting lighter. My CM just became egg white today also.

. So I’m wondering if I missed my window.