So you have finally seen that all-important positive result from the pregnancy test, or perhaps your body is showing all the tell-tale signs that a baby is on the way, but just how pregnant are you? It is always handy to know when your little one is expected to make an appearance into the world and there are several ways to do this, whether it is asking your GP or using a pregnancy calculator. However, remember that none of these are a 100% guarantee as babies tend to come when they want to not when you tell them to...

Put pen to paper

If you know your menstrual cycle then you can work out your baby’s due date. A normal pregnancy lasts 38 weeks from the day of conception. However, knowing the exact moment the sperm met the egg is difficult so it is worked out by counting from 40 weeks after the first day of your last menstrual period, assuming that women have 28-day cycles and that conception took place on the 14th day. As you can imagine, this is all very approximate, particularly as a baby is considered full term at 37 weeks.

Pregnancy calculator

Using a pregnancy calculator is a quick and easy way of working out your due date. Simply find a pregnancy calculator online, type in the exact date of your last period, click a button and it will work out the most likely date your baby will arrive. Then you can plan the rest of your pregnancy, using the wealth of month-by-month advice also available online.

Scan

Mums-to-be are offered a dating scan from between ten and 14 weeks of pregnancy. During this, the sonographer carrying out the scan will work out how pregnant you are by looking at your baby on the screen but even then it can be off by a week or more depending on the abilities and accuracy of the technician and the size of the baby. Most babies grow at the same rate in the first 12 weeks but the size corresponds less and less as the pregnancy continues so further scans can become even more inaccurate.

Not an exact science

It is important to remember that your due date is not set in stone and to try and not get stressed or upset if you end up going beyond it. Remember, fewer than five per cent of babies actually arrive on the date they are due.

Author's Bio: 

Debra Aspinall is an experienced journalist and the editor and leading writer for the Emma’s Diary website, one of the UKs foremost pregnancy and baby websites. Debra writes on pregnancy related topics such as signs of pregnancy, stages of pregnancy and advice. She also writes on women’s health and beauty issues and contributes travel articles to glossy magazines in London and the Home Counties.