⚠️ Cyluna is an informational tool, not a medical service. The content on this site — including all calculator outputs — does not constitute medical advice and should not be used as a substitute for professional healthcare.
Who we are
Cyluna (mycyluna.com) is a free menstrual health information website. It was created to help people understand their menstrual cycles through educational content and estimation tools. Cyluna is not a healthcare provider, medical practice, or telemedicine service.
Informational purpose only
All content on Cyluna — including articles, calculator results, date predictions, and health information — is provided for general informational and educational purposes only. Nothing on this website is intended to:
- Diagnose any medical condition
- Treat, cure, or prevent any disease
- Replace the advice of a qualified healthcare professional
- Provide a basis for medical decision-making without professional consultation
Calculator results are estimates
The cycle calculators on this site use established medical formulas (including Naegele's Rule for pregnancy due dates and standard luteal-phase calculations for ovulation). These are the same formulas used in clinical practice as starting points — but they are statistical averages, not certainties.
Actual cycle length, ovulation timing, and pregnancy progression vary significantly between individuals and can be influenced by stress, illness, hormonal conditions, medications, and many other factors. Calculator results are estimates only and may not accurately reflect your individual situation.
Individual cycles vary
A "normal" menstrual cycle can range from 21 to 35 days. Period duration can range from 2 to 7 days. Ovulation timing varies even within regular cycles. These tools assume average hormonal patterns that may not apply to you — particularly if you have a hormonal condition such as PCOS, endometriosis, thyroid disorders, or if you are perimenopausal, postpartum, or have recently stopped hormonal contraception.
When to consult a healthcare provider
Always speak to a qualified doctor or healthcare provider if you:
- Have missed more than one period and are not pregnant
- Experience sudden changes in your cycle pattern
- Have severe or worsening period pain
- Are trying to conceive and have been unsuccessful for 12 months (or 6 months if over 35)
- Have symptoms suggesting pregnancy (positive test, nausea, breast changes)
- Are experiencing symptoms of a hormonal disorder
- Have any concerns about your reproductive or general health
Seek emergency medical care immediately if you experience:
- Sudden, severe abdominal or pelvic pain
- Heavy bleeding that soaks through a pad or tampon every hour for two or more consecutive hours
- Signs of ectopic pregnancy (sharp one-sided pelvic pain, shoulder pain, dizziness, faintness)
- Symptoms of miscarriage in a known or suspected pregnancy
No doctor-patient relationship
Use of this website does not create a doctor-patient or therapist-client relationship between you and Cyluna or its founder. Any communication through the contact form is not confidential medical communication and will not be treated as such.
Third-party references
Cyluna references clinical guidelines from NHS, Mayo Clinic, ACOG, and other recognised health authorities. These references are for informational context only. Cyluna is not affiliated with, endorsed by, or acting on behalf of any of these organisations.
Limitation of liability
To the fullest extent permitted by law, Cyluna and its founder accept no liability for any loss, harm, or adverse outcome arising from reliance on the information, tools, or content provided on this website. Your use of this site is entirely at your own risk.
If you have questions about this disclaimer, please contact us. If you have a health concern, please speak to a qualified healthcare provider.
Last reviewed: April 2026. We update this page when material changes are made to our content or tools.