The time between ovulation and the next period is called the luteal phase. A very typical luteal phase is 14 days, although it does vary from woman to woman -- anywhere from about 10 days to 16 days. For most women, the length of their individual luteal phase stays pretty much consistant month to month. That's why you can be quite sure that you're pregnant if you don't get a period after 17 days after ovulation (assuming your temperature stays high).
By comparison, the phase prior to ovulation can vary dramatically month to month for a woman. It is very unusual that a woman has a "normal" 14 days leading up to ovulation, month after month, year after year. More typically, the time varies occassionally - by days or even weeks - based on things going on in the woman's life -- illness, stress, nutrition, etc. That's why the rhythm method of birth control doesn't really work.