Safe Period: How to Calculate It

Laying your cards on the table and declaring that you don’t want a child (or another)? Then, when is the safe period in which you can have sex without worrying about pregnancy and the unsafe days you should avoid? Let’s find out how to calculate them!

When is my safe period?

menstrual cycle hormone level luteal phase period follicular phase

The safe period is considered the period in a woman’s menstrual cycle where conception is very unlikely; the unsafe period is when the possibility of getting pregnant is very high. The unsafe period refers to about a week before and after ovulation, and the safe period is the rest of the menstruation cycle.

The reason why the unsafe period spans about two weeks is because sperms can live for up to about 5 days after being ejaculated into the vagina. Also, ovulation can happen a little earlier or later than usual depending on the woman’s physical condition. Putting all this together, around a week before and after ovulation is considered an unsafe period.

How to calculate safe period

menstrual cycle ovulation period
There are in total 4 ways to calculate when your safe and unsafe days are. All of the 4 ways are based on calculating when ovulation occurs.

1. Rhythm method

The rhythm method was discovered independently by both Hermann Knaus and Kyusaku Ogino. It is based on the idea that ovulation takes place between 12 to 16 days before the due date of the next period.

This method is more suitable for women with regular menstrual cycle whose due date of periods can be calculated relatively accurately.

2. Cervical mucus method

The cervical mucus method helps you track the changes in your cervical mucus to determine when ovulation is. Cervical mucus refers to vaginal discharge, and to check it, you will need to check your cervical mucus at the opening of your vagina with your fingers or a piece of tissue. (Make sure you wash and disinfect your fingers before doing so.)

As you approach ovulation, cervical mucus increases in volume and also becomes stringier. In contrast, cervical mucus after ovulation is relatively scant and sticky.

3. Basal body temperature (BBT) chart

Measuring your BBT once you open your eyes in the morning is another method of predicting when ovulation occurs. Once a month, you might see a huge dip in BBT from low levels to an even lower level before entering a period of high body temperature. The dip happens on ovulation day or 1 to 2 days before ovulation day.

4. Ovulation predictor kit (OPK)

The luteinizing hormone (LH) levels increase 36 hours before ovulation, and
OPKs react to the increased LH levels. OPKs can be found in drugstores and obtained online easily to help you predict when your ovulation day is.

Possibility of getting pregnant during unsafe period

It’s said that not using any contraceptives in sexual intercourse during your unsafe period gives you a 20 to 30% chance of getting pregnant. If you have intercourse throughout the year without thinking when the unsafe period is, the odds of getting pregnant are about 85%.

This percentage changes depending on the age of the woman. Those in their 20s have a higher probability of becoming pregnant, while those in their 30s have a 20 to 25% chance of conceiving and those in their early 40’s have a 5 to 10% possibility of becoming pregnant.

Think of safe period just as a reference

couple talk
Think of the distinction between “safe” and “unsafe” periods as a reference. There are many who go to fertility clinics and still aren’t able to get a grasp of the “best” timing to try and conceive – so, it’s only inevitable that ovulation dates are calculated wrongly sometimes.

If you’re not yet ready for a baby or don’t want a baby, then use contraceptives when you can. This will help put you at ease. Talk to your partner and make sure you plan well about how to get pregnant or how to avoid pregnancy.