The nausea and sometimes vomiting during pregnancy often starts between 4-6 weeks and may last until weeks 12-14 or beyond. Since there are so many changes going on in your body during this time,  nobody has been able to nail down a precise cause, but it sure can be annoying and get in the way of you getting needed nutrition into your body.

Avoid greasy and spicy food during this time, and use bland foods especially in the morning. Dry toast or soda crackers upon arising may help "mop up" the gunk in your tummy and settle things down. Eating four smaller meals per day four hours apart may work better than three meals per day. ...