Cycle to cycle variation in P4 levels Bungum L et al., Data on file Daytime variation in mid‐luteal serum progesterone IVF patients Patient 7 and 8: 17 and 18 follicles resp ‐ Mid‐luteal P4 levels: 36 and 56 nmol/l resp. Thomsen LH et al, Frontiers in Endocrinology, 2018 66 63