Talk to your midwife, GP or obstetrician about any concerns you have.
For many women, ultrasound scans are the highlight of pregnancy.
Pregnancy and the fetal heart can be seen from six weeks gestation by vaginal scan and from eight to nine weeks by abdominal scan.
Accurate measurements and images are taken of the gestational sac and the 'crown to rump' length of the embryo, to accurately date the pregnancy.
Most scans are carried out by specially trained staff called sonographers.
Also, find out more about getting help if you're not getting pregnant.Ultrasound scans use sound waves to build a picture of the baby in the womb.The scans are completely painless, have no known side effects on mothers or babies, and can be carried out at any stage of pregnancy.A chorionic villus sampling diagnostic test (CVS) is performed at 11 - 14 weeks.Using ultrasound guidance, a sample of tissue is taken from the placenta, either using a needle inserted through the abdominal wall or fine forceps through the cervix.