Headaches are a very common symptom during pregnancy and I hear they get worse in your third trimester. A lot of women experience their very first migrane during pregnancy as well.
Hormone levels rise dramatically in early pregnancy, and can contribute to headaches. Changes in your blood circulation and blood volume during pregnancy can cause increased pressure on your blood vessels. This increase requires greater fluid intake to counteract dehydration, which can be another cause of headaches. Be sure to get at least 8 glasses of water a day.
It is indeed possible that headaches can be a symptom of pregnancy. Experiencing headaches during pregnancy is one of the most common discomforts and complaints. Headaches may occur at any time during your pregnancy, but they tend to be most common during the first and third trimesters.
An increase in headaches during the first trimester is believed to be caused by the surge of hormones along with an increase in the blood volume circulating throughout your body.