Menstrual Cycle

The menstrual cycle begins on the first day of bleeding and ends the day before the next bleeding

The menstrual cycle begins on the first day of bleeding and ends the day before the next bleeding

In a woman, fertility depends on the menstrual cycle. The menstrual cycle is defined as the time frame from the first day of the menstrual period (menstrual period=menses=bleeding) until the day before the first day of the next menstrual period.
Your first cycle day (CD) is the first day you see bright red blood. Brown spotting does not count.
The menstrual cycle is controlled by female hormones, which are substances produced by the body. These hormones, which include estrogen, progesterone, LH, and FSH, control certain functions of the ovaries and the uterus. Each month they cause the lining of the uterus to build up, several eggs to mature in the ovaries to create a follicle -- and one egg to eventually "pop out" of the follicle, which is ovulation. Ovulation is the event when that egg (sometimes it's more than one) is released from the ovary. Although most menstrual cycles last about 28 days, normal cycles may last between 21 and 35 days.
The follicular phase (or proliferative phase) is the time between the first day of your period until ovulation, and the luteal phase is the time after ovulation to the next period.
The length of the luteal phase usually the same for most women around 14 (plus/minus 2) days.
What counts is the time from the first day of the period until ovulation, that is the proliferative phase. The proliferative phase is different from one woman tho the next and even in one woman it can change from one month to the next. So if your cycle is usually 32 days then you subtract 14 from 32 and you get 18. So you would expect to ovulate 18 days after the first day of your period.
BabyMed has the best calendar to calculate your ovulation.

BabyMed Calendar