Then it is helpful for you to know when you will next ovulate. The best time to successfully fertilise an egg cell is one day before ovulation. During a cycle, you are fertile for a total of around 6 days.
It is possible to have a certain influence on whether you will have a boy or a girl.
At the moment when the egg and sperm cells join, the gender of the child is already fixed. What is decisive is whether a sperm cell with an X-chromosome (=female sperm cell) or with a Y-chromosome (=male sperm cell) penetrates into the egg cell.
The egg cell always contains an X-chromosome, so that the combination XX produces a girl and the combination XY creates a boy.
The female and male sperm cells have different properties:
- female X-sperm cells are larger, stronger, slower and survive longer
- male Y-sperm cells are smaller, weaker, faster and do not survive as long
Do you want a boy?
The best time to have sexual intercourse is at the time of ovulation (or shortly before or afterwards). The probability of producing a boy with the fast male sperm cell is greater then.
Do you want a girl?
The best time to have sexual intercourse is around three days before ovulation. The chance of having a girl is greater at this time, as the “more durable” female sperm cells have a better chance of “surviving” until then.
Ovulation takes place around the middle of the cycle. To determine when this is, you need to keep a menstruation calendar. As the cycle is not always the same length of time, it is necessary to take 6 to 12 cycles into account and to determine the shortest and longest cycles among these.
How can you calculate your fertile days?
First fertile day: Your briefest cycle minus 18 days
Last fertile day: Your longest cycle minus 11 days
First fertile day: 27 days -18 = 9;
Last fertile day: 30 days - 11 = 19
That means that you are fertile between the 9th and 19th day in the cycle.
The cycle may change due to a number of factors, such as stress, psychological strain, illness, etc., so that this method is only meaningful if you have been keeping a note of your cycle in the menstruation calendar for at least 6 months. Due to these fluctuations, the calendar method is very unreliable as a means of contraception.
You can also have your fertile days calculated quickly and easily online! Simply go to our ovulation calendar and enter the first day of your last period and the average length of your cycle.
This method makes use of the fact that the body temperature rises around two days after ovulation and remains elevated until menstruation begins.
One speaks of a temperature increase when the body temperature is at least 0.2 °C higher on 3 consecutive days than it was during the 6 days before.
However, body temperature is also affected by the consumption of alcohol the night before, illness, lack of sleep or taking medication.
How and when should the measurement be carried out?
You should have had at least 5 hours sleep before taking the temperature measurement for at least 3 minutes in the morning shortly after waking up and while you are still lying in bed (=waking temperature). The following measurement methods are suitable:
- Measurement taken in the vagina (vaginal)
- Measurement taken in the rectum (rectal)
- Measurement taken in the mouth under the tongue (oral)
A measurement under the arm is too imprecise.
It is important that you always take the measurements at the same time each day and using the same measuring method in order to compare the values later!
Enter the measurement values in a cycle calendar, so you can track the temperature development. You are fertile 2 days before the rise in temperature and for around 3 days afterwards. So that you can foresee these days, you should fill in this calendar for at least 6 months.
Dr John J. Billings and his wife Dr Evelyn Billings discovered that the consistency of the cervical mucus changes during a cycle, thereby making it possible to determine when women are at their most fertile.
- Following menstruation, only a little mucus is produced; the vagina is more on the dry side.
- A few days prior to ovulation, mucus production increases. At this time, the mucus is milky or yellowish, viscous and sticky. It is difficult for sperm to penetrate this mucus.
- As the fertile days approach, the mucus becomes clearer and thinner. The vagina feels moist.
- Following ovulation, the mucus becomes milky and viscous again.
What consistency should the mucus have?
To assess cervical mucus, you should remove some mucus from the entrance to the vagina or from the vagina itself. Hold the mucus between your thumb and index finger and slowly pull them away from each other. If you are able to pull mucus threads of several centimeters in length (much like spinning a spider’s web), ovulation is about to take place.
This method combines analyses of the cervical mucus, the cervix and the uterine orifice with body temperature measurement.
How do the cervix und uterine orifice change?
The consistency of the cervix and uterine orifice likewise changes during a cycle.
On infertile days, the cervix and uterine orifice are firm and closed and lie low in the vagina. If you insert one or two fingers into the vagina, you easily feel this.
As your fertile days approach, the uterine orifice becomes softer and opens a little (like lips). The cervix moves much further up into the vagina.
By carrying out this self examination, you can complement the analyses and measurements of the other methods, allowing you to predict fairly reliably when you will ovulate.