CD 21 blood test anyone know???

Corkee • 🌈 Mother to a beautiful rainbow baby 🙏🏻

I'm getting tests done to see why im not getting pregnant. I will have a blood test on cd21 and my husband will have a sperm test. What in the blood are they looking at on cd21? Any tips on increasing or improving sperm count? My partner has never smoked or drank his life and works out in the gym everyday...