Carrie, I found this at familydoctor.org :
Morning sickness refers to the nausea and vomiting that some women have when they become pregnant. It is caused by the sudden increase in hormones during pregnancy. Although morning sickness is more common in the morning, it can last all day for some women.
How long will morning sickness last?
Morning sickness is very common early in a pregnancy (usually beginning around the 6th week). It tends to go away later in pregnancy, and it's almost always gone by the second trimester (the fourth month). But there isn't a set time for it to stop because each woman is different, and each pregnancy is different.
Will morning sickness hurt my baby?
It shouldn't. Morning sickness can become more of a problem if you can't keep any foods or fluids down and begin to lose a lot of weight. Many doctors think morning sickness is a good sign because it means the afterbirth (the placenta and fetal membranes) is developing well.
Tips to relieve morning sickness
The tips below may help reduce morning sickness.
Eat small meals throughout the day so that you're never too full or too hungry.
Avoid rich, fatty foods.
Avoid foods with smells that bother you.
Eat more carbohydrates (plain baked potato, white rice, dry toast).
Eat saltine crackers and other bland foods when you feel nauseous.
Try gelatin desserts (Jell-O), flavored frozen desserts (popsicles), chicken broths, ginger ale (nondiet), sugared decaffeinated or herbal teas, and pretzels.
The iron in prenatal vitamins can bother some women. If you think your morning sickness is related to your vitamins, talk with your doctor and he or she may change your vitamins.
Wearing "acupressure" wrist bands, which are sometimes used by passengers on boats to prevent sea sickness, may help some women who have morning sickness. You can buy the bands at boating stores or travel agencies.
If these tips don't give you relief from morning sickness, your doctor may have other ideas. Keep in mind that morning sickness doesn't mean your baby is sick.
Good luck with TTC!