I went to A&E after first attack. I honestly thought I was going to die. They checked me out and when they couldn't find anything in the way of high BP, brain tumour, stroke etc, They refered me to the ophthalmic docs. After they examined me they said all was well but it was an optical migraine. They are often stress induced.(hence my first one when stuck in the car with 3 screaming kids!)
I would get yourself checked out if your worried just to give you peace of mind. The worry will probably make them happen more!