The term "morning sickness" refers to the nausea and occasional vomiting that women experience during pregnancy. Contrary to popular belief, morning sickness doesn't occur only in the morning. In fact, many pregnant women experience morning sickness throughout the day. Morning sickness is thought to be caused by an increase in hormones during pregnancy. The surge of estrogen, progesterone and HcG may contribute to the vomiting and nausea that many pregnant women experience.
If you are wondering when you will experience morning sickness in pregnancy, remember there is a chance you might never have any symptoms of morning sickness at all throughout your pregnancy. If you do, most women experience it approximately at 6 weeks of pregnancy. Some women have said they experience morning sickness as early as 3 1/2 weeks of pregnancy - just a few days after conception, and right around implantation. Some women won't feel any morning sickness until 8 weeks of pregnancy. And, as mentioned earlier, some women don't ever feel nauseous at all. In fact, 40 percent (or more) of pregnant moms don't experience morning sickness at all.