The luteal phase of the menstrual cycle is about the same length in most individuals (mean 14/13 days, SD 1.41 days) whereas the follicular phase tends to show much more variability (log-normally distributed with 95% of individuals having follicular phases between 10.3 and 16.3 days).he length of a woman's menstrual cycle typically varies somewhat, with some shorter cycles and some longer cycles. A woman who experiences variations of less than eight days between her longest cycles and shortest cycles is considered to have regular menstrual cycles.
Iambic pentameter is a commonly used type of metrical line in traditional English poetry and verse drama. The term describes the rhythm that the words establish in that line, which is measured in small groups of syllables called  feet . line of iambic pentameter is made up of five such pairs of short/long, or unstressed/stressed, syllables. Iambic rhythms come relatively naturally in English.
There is a popular rhythm called iambic pentameter that Shakespeare often used, which is a line that consists of five iambs, otherwise known as ten syllables in a alternating pattern of unstressed and stressed beats.