OPK lines seem to be getting lighter and it's only my second day off of my period. HELP!!!

Alecia • Happily married since 2012. We have two beautiful daughters, Sophie 6/10/12 and Addilyn 9/29/15. 💕
So today is only the second day off of my period, but I took an opk yesterday morning, another one this morning and just took another one this afternoon. It seems like it's getting lighter in color and not darker. What do you all think? I've been off of Seasonique for going on two months and my husband and I are in the process of TTC, so seeing this line get lighter instead of darker freaks me out. This is also my first time using OPKs so I'm not really sure what to expect besides the line needing to be darker or as dark as the test line.