Confused

Malina • Mommy to Serenity, Harley and my Angel baby Ava. 👼🏽 💞

My OPK’s only get dark when I use my second morning urine. They’ve been getting darker when I do that time of day but I decided to take one just now at 5pm after a 3 hour hold and it’s super light. Why do they only work for me with second morning urine? What’s going on?