The luteal phase and ovulation are both different parts of a woman's monthly cycle. A luteal phase is the time period ranging from the first day of ovulation to the day before the menstrual period starts. Ovulation occurs once a month when a woman releases an egg from her ovarian follicle, which travels through the fallopian tube. This is typically the time when pregnancy is most likely to occur. If the sperm doesn't fertilize the egg within a day after its release, it starts to break down and will come out of the body during the menstrual period.
Women who are trying to conceive typically try to keep tabs on exactly when the luteal phase and ovulation begin. The luteal phase can usually be depended on to last the same amount of time each month, which is often around 14 days for most women. The onset of ovulation can be more unpredictable, and may not begin when expected due to illness, stress, or medication. Most women can tell when they are ovulating by keeping track of their basal body temperature throughout the month because this temperature typically increases by a half or full degree during that time. Once ovulation has begun, the luteal phase will begin and last until the next period starts.
A woman can use an ovulation calendar to track the length of her luteal phase and ovulation onset for each month. It is important for a woman to know how long her cycles usually are for these calendars to be accurate. If the ovulation calendar is accurate, it gives most women a good idea of exactly when they can expect to ovulate every month. To use the calendar, a woman simply takes the length of her cycle and subtracts the length of her luteal phase. The number that results will typically be the day ovulation begins.
In some cases, it may be hard to track the luteal phase and ovulation on an ovulation calendar because some women have unpredictable menstrual cycles or are unsure exactly how long their luteal phase lasts. Most doctors recommend using a 28-day cycle and 14-day luteal phase, which is the average for most women, if the cycle varies from month to month. Women who have luteal phases that are too short or too long may have trouble conceiving, but a doctor can prescribe progesterone therapy to help with this. A luteal phase that is too short is less than 10 days, and a luteal phase that is too long is in excess of 16 days.