Parenting
Morning sickness can occur at any time of the day, although early morning is a common time.
Sickness can start before you miss your first period, but it's typical to feel much better after three months. Not everyone's so lucky - some women are sick throughout their pregnancy.
It's believed pregnancy hormones cause the sickness. These circulate in the body, affecting all your organs and preparing your body to sustain new life.
One theory is that your body is protecting the foetus from harmful substances. In fact there's research to show how women who experience bad sickness are less likely to miscarry, and the sickness generally stops when the baby's major organs have developed.
You should talk to your doctor if your sickness is affecting your overall health, if you find you can hardly keep food or drinks down, or if you become extremely tired.
Extreme pregnancy sickness, or hyperemesis gravidarum, might even mean a hospital stay to allow you to maintain fluid levels and prevent dehydration. Drug treatment is available in some cases.
Pregnancy sickness, even severe sickness, is not associated with any harm to your baby.