A: Vomiting (or emesis, as us docs like to call it) during pregnancy happens to most women. Vomiting 17 times in a day, however, is not common or normal. If you are vomiting this much in the first trimester, you may have a severe form of morning sickness called "hyperemesis gravidarum." If you are vomiting 17 times a day and are in the second or third trimesters, you could be suffering from food poisoning or other medical or obstetric complications. If you are unable to keep liquids down for more than 6 to 12 hours, it is very important that you call your practitioner to alert her.