Audrey,
What kind of doctor did you see? Your family doctor? He may not have known enough about Migraine to answer your questions, but if that's the case, he really should have said so.
In general, aura lasts 60 minutes or less, and the aura symptoms fade when the headache phase starts. That's in general, and it may not always happen that way.
Yes, it does sound like Migraine with aura, but that has to be confirmed by a doctor.
You might also want to take a look at Migraine with Aura - The Basics.
Tests such as MRI are generally "normal" in Migraineurs. That's one of the problems. There is no diagnostic test to confirm Migraine disease. Diagnosis is done by reviewing your and your family's medical history, reviewing your symptoms, and ruling out other causes of those symptoms.
You didn't say which medication your doctor gave you, but its not working doesn't mean you're not having Migraines. None of the medications work for everyone.
Hope this helps,
Teri