Ehh, honestly 40.4 nmol/L on CD21 tu agak low for confirmation of ovulation lah, biasanya doctors look for minimum 30 nmol/L but ideally lebih tinggi untuk confirm ovulation yang proper happened. Few of my mum friends who did fertility tracking, their progesterone readings were dalam 60-100 range on CD21, so your result might indicate ovulation didn't happen strongly or maybe timing test-nya off sedikit. Best to discuss directly with your doctor lah because they'll look at your full cycle pattern and maybe suggest repeat testing, depending on your situation!