Women Supporting Women
• Campaigning for better births for all
• Protecting human rights in childbirth
• Independent information about pregnancy and birth
• Raising awareness of research

For a better birth

Latest Content


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What has the AIMS campaigns team be…

AIMS Journal, 2021, Vol 33, No 4 By the AIMS Campaigns Team Covid-19: With other members of the But Not Maternity Alliance [1] we wrote to all Trusts and boards that were…

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Aims Editorial December 2021: What…

AIMS Journal, 2021, Vol 33, No 4 Alex Smith The title of the editorial for this issue of the journal is, ‘What just happened?’ I feel a little bit like ‘baby bear’ from G…

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How does BMI influence maternity ca…

AIMS Journal, 2021, Vol 33, No 4 [ All charts are taken from or adapted from the report ] By the AIMS Campaigns Team The National Maternity and Perinatal Audit (NMPA) is…

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AIMS 60th Anniversary Event - Confe…

POSTPONED FROM JUNE 2020 Making a difference past and future The purpose of the day is to celebrate what Birth Activists in general and AIMS in particular have achieved,…

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Latest Campaigns

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AIMS Campaigns Update, December 202…

AIMS supports the Government's ongoing commitment to the implementation of relational care - the Continuity of Carer model of care - in the maternity services across Engl…

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Response to the RCOG Consent Advice…

The draft document can be found here General comments: The comments form is online only and cannot be downloaded. This makes it very difficult for considered responses to…

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AIMS Position Papers

AIMS is pleased to announce the publication of the first of our new position papers. Over the years, AIMS has developed a reputation for taking a position on a wide range…

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Pregnancy Calculator i

When's your due date?

What does your "due date" mean? How long is a normal pregnancy? How might being given a due date affect you and your baby? Enter the first day of your last period to discover when you're most likely to give birth.... and to find out more about due dates, induction and "post date" babies.
You are weeks pregnant.
Date of the first day of your last period
Adjusted cycle length

Date of the first day of your last period

The date of your last period allows an estimation of when you ovulated and conceived your baby.

A surprising number of women will have a bleed after they are pregnant, and although seeking advice from a doctor or midwife is recommended, usually this bleeding is not a problem.

Adjusted cycle length

Your menstrual cycle is counted from the first day of one period to the first day of the next. The average menstrual cycle is 28 days long, but many women will have longer or shorter cycles than this.

Ovulation usually takes place about 14 days before the next period. This means in a short cycle ovulation will be less than 14 days after your last period and with a long cycle more than 14 days after your last period. Giving the length of the cycle allows this to be taken into account in calculating your due date.

Many women have irregular cycles which make using the last day of their period less reliable for estimating due date.