Glad your feeling a bit better Peri - I think there are many causes of migraine and it differs from person to person. Mr. Den gets them a lot lately -he can go about a month with nothing and then bam he will have 2 or 3 on and off for 1 to 2 weeks.
I also get them, sometimes with the flashing lights, but other times just a dizzy feeling comes on. Then the horrible headache. Mine are definately hormonal though - even though having a hysterectomy 13 years ago, I am still in menopause mode and get migraines certain times of the month. Very strange.