Fig. 1
From: The natural menstrual cycle revisited – can natural cycle be trusted
Number of cycles with a progesterone level ≥ 30 nmol/L on cycle day 20 or 25
Fig. 1 | Journal of Ovarian Research
From: The natural menstrual cycle revisited – can natural cycle be trusted
Number of cycles with a progesterone level ≥ 30 nmol/L on cycle day 20 or 25