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  • natural infertile days when the sexual intercourse does not lead to conception
  • for spouses who do not want to conceive a baby
  • independent of the menstrual cycle (period)
  • suitable also for women after childbirth
  • based on natural rhythm – no medication is taken
  • no negative effects on body
price: 27€


  • create a user account
  • fill out your personal data in the form (date of your birth, previous pregnancies, etc.)
  • to pay the fee for the calculation (27€): by credit/ debit card, PayPal or bank transfer
  • the calculation is made and activated in your account within 3 days after the data and the payment have been received


  • one year infertility chart beginning with your last period; if your period is absent (e.g. due to childbirth), the calculation will start from the current month
  • the calculation also contains instructions that need to be followed
  • the interactive calendar on webpage app (in your account) that you can use in your mobile device


Jonas method of Natural conception control is correct in 98,6% of cases.

All data needed for a calculation are strictly confidential (medical confidentiality) and are used for the calculation only.

I do not have my period yet after giving birth, can I still get pregnant again?

Even nowadays we encounter misinformation that if a woman is not menstruating after she had a baby, she cannot get pregnant. It's not like that.
Even while breastfeeding and despite the absence of menstruation conception can occur. The earliest case of pregnancy we recorded was 5 weeks after delivery.

I had a baby a month ago and we are planning to conceive another baby in half a year. Should I ask for a Contraception Calculation now and only then a Gender Selection Calculation?

Calculations are made for one year. If you are planning another child during this period, the Gender Selection Calculation is appropriate for you.
You will first use it as a Contraception Calculation and then you use it to choose the gender of the next baby.

I am interested in the Natural Contraception Calculation

sign me up