Increasing pressure in the back of the head However, if the pain feels like it's concentrated on just one side of your head (a "halfheadache") you may be experiencing what is known as a cluster headache Rare, but debilitating, cluster headaches are a type of headache that happens in cycles (clusters) that can last weeks or monthsMigraine headaches are a common type of headache in pregnancy These painful, throbbing headaches are usually felt on one side of the head and result from expansion of the blood vessels in the brain The misery is sometimes accompanied by nausea, vomiting, and sensitivity to light A small percentage of women with migraines also have an aura New And Sudden Headaches May Be A Symptom Of Covid 19 Headache back of head left side pregnant