SAFE AND UNSAFE GIRL DAY

Safe & unsafe days
The ‘safe days’ method is suitable for people who don’t like any other form of contraception, have sex only occasionally, or who do not terribly mind getting pregnant. Of course, they must also be able to do simple sums.
Safe & unsafe days; avoiding pregnancy without using a contraceptive
If you know what the most risky time of the month is, you can avoid pregnancy without using any contraceptive. This method -also known as ‘rhythm’ or ‘biological’ method- became unpopular with sex educators since the invention of the pill, but it is certainly not as useless as it is sometimes made out to be. It is also good to be informed about the monthly cycle. So first read about menstruation and ovulation.
Safe & unsafe days; knowing your cycle
The unsafe days are the five days before ovulation (because that is how long some sperm cells can survive in the body) and the day of ovulation itself (because the egg cell is fertile only then). So six days a month are unsafe, the other 24 are not. The only problem is that ovulation cannot be precise predicted and may vary for different reasons (stress or illness, also young girls and older women are often very irregular).
So it is first necessary to know how many days -on average- your menstrual cycle is and how regular it is. If you note down the first day of the period for twelve months, you have a good basis for using the table on this page.
Safe & unsafe days; some examples

If your cycle was always precisely 28 days, your first unsafe day is 11 and the last is 18
If your shortest cycle was 21 days and your longest 33, your first unsafe day is 4 and your last unsafe day is 23
You now understand why this method is not very good if you have irregular periods. And also why it is possible to conceive in the first week, while one is still menstruating. But of course that is quite rare.
Safe & unsafe days; the moment of ovulation
Some women can feel their ovulation as a sharp pain, some feel changes in the breasts, skin, mood or sexual desire. After a day they will be safe.
Women can also measure their body temperature to get an indication of the time of their ovulation.
Body temperature rises slightly after ovulation. The rise is not more than about 0.2 degrees (0.4 degrees Fahrenheit). There are digital thermometers which can show the small difference easily. To use this method correctly, you need to take your temperature every day as soon as you wake up.
The fertile time ends when you have recorded temperatures for three days in a row, which are higher than all the previous six days.).
Make sure that there are no other causes for a rise in temperature.
There are fertility devices on the market, which monitor changes in temperature urine on saliva. The best-known is called Persona. It is a small handheld monitor with a series of urine test sticks. Persona predicts the fertile and infertile times of the menstrual cycle with reasonable accuracy.