It confirms the pregnancy, checks whether it is one child or more and calculates the date when the baby is due.

It is especially important to have this done if bleeding or pain has occurred, or if the likelihood of an ectopic pregnancy exists.

Please therefore, try and drink around 1 pint of water 1 hour prior to your scan.

•check your baby's heartbeat •check whether the pregnancy is intrauterine (not ectopic) •confirm the identification of a single or multiple pregnancy •measure baby to confirm gestation and provide you with an estimated due date (EDD) •allow you to more accurately plan for additional tests such as Nuchal Translucency A full bladder is required for this scan.

This does not necessarily mean that there is something wrong; many scan findings just need a 'second look' for reassurance.

The sonographer will inform you of any such uncertain findings and discuss what your options are.

Between 14 weeks and 20 weeks you can have a reassurance scan if you experience any bleeding and/or pain.

This scan will check the fetal heartbeat and measure the head, tummy and leg length and the amount of amniotic fluid.

ive got my 12week scan on 26th so will be interesting to see what estimated due date they'll give me. when i was pg with dd had an early scan and was told 9 weeks then and wasnt offered a dating scan after that??? they date them by 'size' as on an aveerage until a baby gets to 20 weeks they all develop at a simalr rate.

when i had my 20 week scan i was measuring 3-4 days further but kept it at same date. very early scans can be a few weeks unaccurate as the baby is so tiny but 12 week scans are normally quite accurate but obviously they can be a few days out either way.

The checklist includes the brain, face, heart, lungs, bowels, stomach, kidneys, bladder, arms, hands, legs, feet, spine, the placental position, cord insertion and the amount of amniotic fluid.

i had an early scan last week as had lots of right sided pain and if i went by 1st day of last period i would have been 7 5weeks but the little one was measuring at 8 6weeks!

Obviously it depends on when ovulation occured but if they have given you 9th July that's what I would go with.