Hello madam, I read your query carefully and understood your concerns. You mention to have had the flu injection but you got flu for over 3 weeks now - you are 35 weeks pregnant - you have a severe headache and swollen left eye. Although you take the flu vaccine this does not mean that you can t get flu infection. The vaccine uses the viruses strains that have been causing past flu infection. There are various strains of flu viruses which changes over the time, causing new flu infections that the vaccine can t cover. This is why you are having flu. A headache is a common symptom in flu. It occurs alongside with other symptoms. The immune system raises the body temperature in order to fight infection. This makes the blood vessels dilate and raise the intracranial pressure that causes headache. Also, the inflammation of nose mucosa increases pressure around face and eyes and make you feel a worsen your headache. I would like to know if you have other symptoms and what medications have you taken. What other improvements or recurrences have you seen during these 3 weeks? If your left eye has got swollen and not improved, please get it checked by eye specialist. Meanwhile, make sure to drink plenty of fluids and take a lot of rest. Pregnant women gets flu easily and take longer to get better. Hope this was helpful. Wish fast recovery. Dr.Albana