We usually think of air pollution as being outdoors, but the air in your house or office could also be polluted. Sometimes a group of people have symptoms that seem to be linked to time spent in a certain building. There may be a specific cause, such as Legionnaire's disease.
Symptoms of early pregnancy can also be similar to symptoms experienced prior to the menstrual period, so a woman may not recognize the symptoms as related to pregnancy. This article describes the most common symptoms of pregnancy in its early and later stages. Medically Reviewed by a Doctor on 12/4/2014.
Quick GuideStages of Pregnancy: See the 1st, 2nd and 3rd Trimesters of Mom & Baby. Pregnancy facts*. 1  A normal pregnancy lasts about 40 weeks and is grouped into three trimesters.  Symptoms of early pregnancy include the absence of menstrual periods, breast changes, tiredness, nausea, mood swings, or other symptoms.