A black woman holding up a calendar with a period cycle marked on it

How to count safe days

By Rose Odengo June 5, 06:23 pm
How many days before and after period are safe? How safe are safe days, really?

Safe days, or the calendar method, as some call it, is a form of contraceptive method women use around the world. This method of contraception relies on women tracking their menstrual cycle and counting days in which she can have sex and avoid conception. But how exactly does it work? Love Matters spoke to Dr Adongo- Meme, a resident gynaecologist at Kenyatta National Hospital to understand how it works.

How exactly do you calculate safe days?

If your cycle length is anywhere between 26 and 32 days, (a cycle being from day 1 of the menses until the day just before the next period), then the fertile days are from day 8 - 19. This is called the standard days' method and should not be used by people with irregular menses, or cycles longer than 32 days or shorter than 26 days.

How can you be extremely accurate on your calculations when you have irregular periods?  

This method requires one to record their menstrual cycle length for a minimum of 12 cycles. The length of the shortest cycle and the longest cycle is used to calculate the fertile window. To estimate the first fertile day, 20 days are subtracted from the shortest cycle length. The last fertile day is calculated by subtracting 10 days from the longest cervical length. For example, if your shortest cycle is 26 days and the longest cycle is 32 days, it means the fertile days would be from day 6 to day 22. That’s a pretty long period to abstain so additional precaution would be needed e.g. barrier methods like the condom.

Is it really a reliable long-term measure for contraception?

Yes, it can be used on a long term basis but requires an immense amount of discipline to execute. It also has a high failure rate of 20% largely due to miscalculations and indiscipline.

Is it possible to still conceive while menstruating?

Anything is possible. But largely no because during your menses the hormones that are responsible for egg maturation and ovulation are largely reduced.

Is it possible to conceive the day after the end of your period?

If it falls within your fertile days, yes.

Are there any easier ways of tracking one's fertility calendar aside from manually calculating it on an actual chronological calendar?

There are the good old cycle beads. They look like a traditional necklace. Those are tailored for the people with a cycle length of 26-32 days. Phone apps are also an option but only after you have recorded a minimum of 12 cycles.

In your medical opinion, what would you recommend are better long-term birth control measures women can use?

There are several and recommending one over another is not quite possible. Contraceptive choice is based on several factors: the desire for children, how many, how far apart, any other medical conditions, weight, allergies, and so on and so forth. There is no 'one size fits all'. It requires evaluation by your doctor and a comprehensive discussion on benefits and risks.


What do you use to count your days? Does it work for you?


Did you learn something new?


Hi, thank you for your question. First, you need to determine how long your cycle is. Your cycle begins on the first day of your period and lasts until the first day of your next period. To notice patterns it is best to track your cycle for a few months. Your ovulation date is usually in the middle, for example, if your cycle is 28 days long your ovulation date is the 14th day. However, if your cycle is longer than 30 days or shorter than 20 days, your ovulation date may be a little harder to calculate.

For a typical 28 to 30 day cycle, day eight through to day 19 are considered to be your most fertile. From day 20 to day 26 to 30 are considered to be your infertile days.

This article should provide more information. Please remember, that using this method can prevent pregnancy but you will still be exposed to STI's. This method is not full proof and pregnancy could still occur.


Hi Moe, thanks for getting in touch and asking a great question. Firstly, it is completely normal to have your menses more than once in one month so you need not worry. Having sex while on your period is also completely normal given that you and your partner are okay with it. Click here to find out more: https://lovemattersafrica.com/making-love/period-sex-no-big-deal
It is important to note though that although the chances of getting pregnant while on your period are very small, it is still possible. Have a wonderful week and stay safe! 

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