After a bad migraine is it normal to be dizzy and lighthead? if so for how long before seeking medical assisants?

Can happen: There is a type of migraine called migrainous vertigo in which the headache and symptoms of vertigo or "dizziness" as some people may describe occur in separate phases. But also just as a direct consequence of migraine headache people can have many symptoms after the pain is resolved so it's all fair game. Up to you really as to whether you should see a doc or not. Migraines can last from 4-72 hrs