Who publishes the site
whatislmp.com is an independent website, and its content is published under the name whatislmp.com. It is not a medical practice or a healthcare provider, and it is not affiliated with the organizations whose guidance it cites.
What the site covers
The site explains what the last menstrual period (LMP) is and how it is used to date a pregnancy. It offers three calculators, each working from the first day of the LMP:
It does not cover ultrasound dating, IVF dating or ovulation tracking.
How content is researched and sourced
- Content is based on published guidance from professional bodies and health services, such as the American College of Obstetricians and Gynecologists (ACOG), the NHS, NICE, the CDC's National Center for Health Statistics and the World Health Organization, and on peer-reviewed studies.
- Every medical statement is linked to its source, and each page lists its sources with the publisher and date.
- The calculators apply published conventions only, and each calculator page explains its method. Results are always presented as estimates.
- Statistics, people, quotes and ratings are never invented.
- Each page shows the date it was last updated.
Not medically reviewed
Content is researched from published guidance and is not reviewed by a medical professional. It is educational information, not medical advice, and it does not replace care from a doctor, midwife or other healthcare professional.
Use of AI tools
AI tools are used to help research and draft the content and to build the site; medical statements are limited to what the cited sources say, and each one is linked to its source.
Corrections
If you find an error, send it through the contact form with the page address and what needs correcting. When an error is confirmed, the page is corrected and its "Last updated" date changes.
Advertising
The site shows ads placed automatically by Google AdSense. It has no sponsored content or affiliate links. How advertising uses data is explained in the privacy policy.