INTRODUCTION
First, one should know the duration of the cycle, i.e. first day of the last menstrual bleeding to the first day of the present menstrual bleeding. This is the duration of the menstrual cycle. This duration varies from person to person & is usually between 26 to 31 days.
The idea behind safe period calculator is to prevent or delay unwanted pregnancy naturally without any side effects. Currently there are a few methods of natural family planning, like less reliable rhythm method and mucus method.In order to calculate safe period you should know little bit knowledge of Menstrual cycle and the time period for which ovum and sperms survive.
THE MENSTRUAL CYCLE
Menstrual cycles have several days at the beginning that are infertile (pre-ovulatory infertility), a period of fertility, and then several days just before the next menstruation that are infertile (post-ovulatory infertility). The first day of bleeding is considered day one of the menstrual cycle. In this safe period calculator, days 1 to 7 and day 21 to rest of the cycle is calculated as "Safe Period" for individuals with regular 26-32 days cycles. Please read the method overview for more information. Proper use of Safe Period Calculation method along with coitus interruptus (withdrawal method or pull-out method) is a suggested as a sin free or green family planning method for couples with self control over sexuality. Withdrawal method is not suggested for adolescents or those having casual sex. Others may use condoms during unsafe days to avoid serious and potentially life-threatening risks associated with the use of contraceptive pills.
WHAT IS REGULAR PERIOD?
Menstrual cycle is regulated by hormones and regular menstrual period occurs every month without any missing periods, depending upon your cycle length. A variation of two to three days between menstrual cycles is normal and for some women, menstrual cycle is repeated almost regularly in every 28 days. Although the period of the menstrual cycle can vary from 21 to 35 days, the average cycle lasts for 28 days
WHAT IS AN IRREGULAR OR ABNORMAL MENSTRUAL PATTERN?
According to American Congress of Obstetricians and Gynecologists (ACOG), menstrual cycles longer than 35 days or shorter than 21 days are abnormal. Menstrual bleeding normally lasts between two and seven days, with the average being five days and periods last for longer than seven days are generally considered as abnormal.
WHO CAN USE SAFE PERIOD CALCULATOR?
If your average menstrual cycle length in last 6 months falls between 26 and 32 and the variation between the shortest cycle and longest cycle during this time is 7 days or less, you may utilize the safe period calculator method for birth control.
WHO CANNOT USE SAFE PERIOD CALCULATOR?
If your average menstrual period length is less than 26 days or more than 32 days and the variation between the shortest cycle and longest cycle during this time is 8 days or more, you may not use this method.
Soon after child birth: you must wait for 6 regular periods, before using this method.
SAFE PERIOD CALCULATOR : METHOD OVERVIEW
The menstrual cycle, is commonly divided into three phases: the follicular phase (pre-ovulatory phase), ovulation, and the luteal phase (post-ovulatory phase). The length of each phase varies from woman to woman and cycle to cycle, though the average menstrual cycle is 28 days. Menstrual cycles are counted from the first day of menstrual bleeding.
The follicular phase (or proliferative phase) is the phase of the menstrual cycle; before ovulation, during which follicles in the ovary mature. It ends with ovulation. The main hormone controlling this stage is estradiol.
Ovulation is the process in a female’s menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum. The time immediately surrounding ovulation is referred to as the ovulatory phase. A woman gets pregnant around the days when ovulation occurs.
The luteal phase (or secretory phase) is the latter phase of the menstrual cycle. It begins with the formation of the corpus luteum and ends in either pregnancy or degradation of the corpus luteum. The corpus luteum is a temporary endocrine structure, involved in production of estrogen and progestogen, which is needed to maintain the endometrium, the inner membrane of the uterus.
The infertility period depends on the life span of sperm and on the life span of the egg. The average time of ovulation is the 14th day of an average length (28 day) menstrual cycle. Ovulation time vary for each individual, and can occur from 12th to 19th day of the cycle. Sperm can live up to 3 to 5 days in a womans reproductive tract, so it is possible to become pregnant if unprotected sex occurs 5 days before ovulation. The life span of the typical egg is relatively short, only around 24 hours. If fertilization does not occur within that time frame, the egg will die.
Ovulation approximately occurs in the middle of the cycle, i.e. duration of the cycle - (minus) 14 days (this also varies).
A week before and a week after the approximate day of ovulation is considered to be Fertile period.
The days apart from this is called the safe periods, where the fertilization does not takes place.
So, to calculate the safe period you must know the fertile period.
Calculation of fertile period: The shortest cycle minus 18 days=1st day of fertile period. The longest cycle minus 10 days= last day of fertile period.
Ex: if a women's menstrual cycle varies from 26days to 31days cycle,
The shortest cycle [26days] minus18days=8th day.
The longest cycle [31days] minus 10days=21st day.
Thus, 8th to 21st day of each cycle counting from first day of menstrual period is considered as fertile period.
Period other than this fertile period in a menstrual cycle is considered as SAFE PERIOD.
If one wants to avoid pregnancy avoid intercourse during fertile period. Safe period is safe for intimate activity.
