Table 4.

Estimated luteal phase length based on positive luteinizing hormone test (N=18,761).

Length of luteal phase (days)	Cycles, n (%)
5	142 (0.75)
6	172 (0.91)
7	206 (1.09)
8	227 (1.20)
9	344 (1.83)
10	543 (2.89)
11	946 (5.04)
12	1565 (8.34)
13	2645 (14.09)
14	3523 (18.77)
15	3696 (19.70)
16	2765 (14.73)
17	1819 (9.69)
18	1380 (7.35)
19	1006 (5.36)
20	809 (4.31)