migraine aura without headache, or something else?

So I've been having some visual and auditory hallucinations on and off, usually not accompanied by headache, except on a few occasions.

It's usually pretty mild; I experience visual "snow" or "static", sometimes accompanied by tinnitus or white noise, as well as a sensation of weakness in my lower body. All of this goes away in a matter of seconds, though, and I can go for months without experiencing any of this, only to have it reoccur in waves...I've had this since I was about 10; I'm almost 18 now...It's also happened that I've experienced facial tingling and twitches (infrequently, but the instances are clustered together) but I'm not sure if that is significant or even related to this.

More recently (for less than a year) there have been a few instances where I have a moderate headache; these usually come with the visual thing and/or pulsatile tinnitus...They are not of migraine proportions, though; they are not so severe that I can't function. They seem to correlate with my menstrual cycle but don't occur every month...

Anyone have an idea of what this might be?