Hormone levels and cycle length vary from one woman to another and from cycle to cycle in the same woman. The number of fertile days displayed each cycle will be personal to you and some women will have more, or less than 4. In a study of 87 women, this is what we observed:
Number of High Fertility days before Peak FertilityNumber of Women 0-457 (66%) 5-922 (25%) 10+1 (1%) No Peak Fertility detected after High Fertility7 (8%) TOTAL87 (100%)