How accurate is the menstrual cycle calculator?

What is a menstrual cycle calculator? Is it accurate?

The premise of using the menstrual cycle calculator is that women with regular menstrual cycles will have a higher accuracy. Generally speaking, the menstrual cycle refers to the period from the first day of menstruation to the day before the next menstruation, which is usually 28-30 days. The menstrual cycle is divided into the follicular phase before ovulation and the luteal phase after ovulation based on the ovulation day. The length of the follicular phase is not fixed, but the luteal phase is fixed at about 14 days plus or minus two days.

The menstrual cycle calculator can calculate the various stages of the menstrual cycle. A cycle is mainly divided into three stages:

Stage 1: Ovulation.

Menstruation lasts about 3-5 days. On the seventh day, the pituitary gland secretes hormones to stimulate the development of the egg. When the egg is mature, the pituitary gland begins to secrete estrogen, stimulating the growth of a group of 3 to 30 follicles. These follicles are supplemented in the last few days of the previous cycle to accelerate growth. When the FSH level decreases, one of the supplemented follicles is selected for ovulation, and it is dispatched immediately after maturity, while the rest wither away, and the first stage ends.

Phase 2: Luteal Phase

The duration of the luteal phase is roughly the same for everyone, that is, the time from ovulation to the next menstrual period. Usually, the menstrual period comes about two weeks after ovulation, which is about 14 days.

The third stage: safe period

The seven days before menstruation and the eight days after menstruation are the safe period for adult women, which is a calculation method used by most people for contraception. In addition to the calendar method that uses the number of days to calculate, there are also the basal body temperature method and the secretion observation method. However, the safe period is not absolutely safe. Sometimes women ovulate earlier or later, and the judgment of the safe period becomes invalid at this time.