A general rule of thumb is that ovulation takes place on the 14th day of a regular 28-day menstrual cycle. This is simple math but for some women, calculating the time between ovulation and menstruation is a slightly more complex task.
The problem with calculating the time between ovulation and menstruation is that many women have irregular cycle or a cycle that lasts more than 28 days. In such cases, ovulation is usually considered to take place 10 to 16 days after the start of the previous menstrual bleeding.
Women are usually able to determine when ovulation is taking place, taking into consideration some body changes. Some experience light abdomen pain and changes in vaginal secretion when ovulation is taking place.
In order to be able to track ovulation and the exact time it takes place, you can follow one of several methods. For a start, ovulation is defined as the time when the ovary discharges an ovum. Ovulation is needed for pregnancy to take place. A woman should be able to track the time when ovulation occurs, in order to plan a pregnancy or respectively – to avoid getting pregnant.
The ovulation period takes place in the middle of the menstrual cycle and last for approximately one to two days. Once discharged, the ovum can survive and be fertilized for up to 24 hours.
To calculate when ovulation is taking place, you need to have average figures about the duration of your menstrual cycle. If the cycle is 30-day long, remove 14 from 30. The result shows that ovulation will take place 16 days after the first day of the previous menstrual bleeding.
This calculation method can be used only in case you have a regular menstrual cycle, regardless of its length.
To find out when ovulation takes place, you can also measure basal body temperature (BBT). Keep in mind that the female reproductive system is very delicate and the exact ovulation date can differ from one menstrual cycle to the next.
Measuring BBT allows a woman to know when her ovulation is taking place, since the temperature registers a slight increase 12 to 24 hours after the ovarian follicle ruptures.
To measure BBT, you need to get your temperature reading before getting up each day. Temperature should be measured during the same time each morning, before you get up, wash your teeth and start getting ready for the day.
Start measuring BBT during the first day of your menstrual cycle (that is, the first day you get a bleeding). Keep track of the daily reading in a chart. During ovulation and slightly before that, BBT increases because of the availability of specific hormones in the body. During ovulation, temperature will go above 36.5 degrees Celsius, in some cases – even above 37 degrees Celsius.
You should also learn to recognize the small signals that the body sends during ovulation. Pain in the abdomen could appear slightly before or during ovulation. The pain appears very low in the abdominal area. It can last from several hours to several days.
Special ovulation tests have also been designed to calculate when the process is about to get started. Such tests can be purchased from every pharmacy.
Relying on the ovulation calendar method to determine the time between menstruation and ovulation is often unreliable. Your menstrual cycle could be disrupted as the result of stress, diet changes and changes in hormone levels. Apart from calculating the days from your last menstrual bleeding, you need to make use of at least one more method to know for sure when ovulation will occur.