Approximately once a month in one, and sometimes in both ovaries of a woman, the following process occurs. From the first days of the cycle several follicles start to grow in the cortical ovary substance. As a result, one of them grows approximately in 10-12 days to the size of forest, and sometimes walnut (12-27 mm on average). When the follicle ripens, an ovum leaves it into the abdominal cavity (ovulation occurs). Fimbria of the uterine tube captures it, and the egg enters the uterine cavity.
Calculation of the moment of ovulation
The simplest method to calculate the day of ovulation with a regular cycle is to divide the number of days of the cycle in half, and the average day plus minus 4 days in each side is the possible days of onset of ovulation. Another method takes 16 days from the cycle time. But this is all very approximate, therefore it is best to determine the date of ovulation by measuring basal temperature, and if necessary, by ultrasound monitoring on certain days of the cycle.
Calculation of ovulation with an irregular cycle
Not always a woman's cycle lasts the same number of days. Hormonal disorders or inflammatory processes of female genital organs can make the cycle irregular. In an irregular cycle, the definition of ovulation can not be accurate for simple counting, when the duration of six non-regular cycles is taken as a basis. The onset of ovulation is possible on one of the following days: in the shortest cycle from its duration, 18 (the first possible day of ovulation) are taken away, and 11 (the last possible day of onset of ovulation) is taken away in the longest cycle.
Ovulation with an irregular cycle - other methods of determining
One of the most accurate methods of determining ovulation is still the measurement of basal temperature . Then, when looking at the ovulation calendar
The second accurate method is ultrasound examination, then in the first phase in one of the ovaries will appear a liquid-filled black ball that will grow and disappear after the onset of ovulation, and a small amount of free liquid will be determined behind the uterus. Two days later it will resolve, but when the dominant follicle breaks, it is the fluid from it that causes ovulatory pain in women, which also may indicate the onset of ovulation with an irregular cycle.