Although it’s known as “morning sickness,” the nauseau that accompanies pregnancy can happen at any time of the day.

According to MayoClinic.com, morning sickness plagues as many as 90 percent of pregnant women at some point during their pregnancy.

For most women, it starts in the first trimester and is gone by the second, although it can last throughout the entire pregnancy. If you are trying to get pregnant, you may be hoping that feeling nauseated is a sign that you are finally pregnant.

When to Expect Morning Sickness

For most women, morning sickness starts about the sixth week of pregnancy, which is about three weeks after conception, assuming you have a normal menstrual cycle. It can start as early as the fourth week, which is right around when you might get your period.

What Causes Morning Sickness

Though there is not yet definitive proof, most doctors believe that morning sickness is related to the human chorionic gonadotropin (hCG) hormone, which pregnant women produce in abundance. You start to produce this hormone after the embryo implants in your uterus and the amount doubles every two days. The more hCG you have in your system, the more likely you are to get morning sickness. For example, women who are pregnant with multiples are more likely to get morning sickness.

Considerations

Feeling nauseated is not always related to morning sickness. You can feel upset stomach if you ate something that didn’t agree with you, if you’re nervous or if you get a viral infection. If you already know you are pregnant, nausea is more likely to signify morning sickness.

Early Sign of Pregnancy

Morning sickness does occur early in pregnancy, and it may be an early sign of pregnancy if you are not trying to conceive. However, if you are trying to conceive, you are likely to be looking for a missed period, which will probably happen before morning sickness occurs. Feeling nauseated before a missed period does not usually signal that conception took place.

Exceptions to the Rule

All women are different, and each pregnancy is different. You may start to get morning sickness earlier than the average woman. If you’ve already had a pregnancy and experienced early morning sickness during that time, you may be able to see nausea as a sign of pregnancy sooner than other women.