That sounds so like mine as I was growing up, same pattern same amount of time for Aura to pass over my vision, then the left arm numbness, then the headache. I am so glad you shared your experience HSSS because that somehow made me feel less afraid, but also, really seems to be the answer to what happened to me. Different yes, but after I had posted, maybe an hour or so, I began having pain (migraine pain) in my right temple. I took my Imitrex because I felt it might help with the numbness. I'm mainly to take it at first sign of migraine, but it also says I can take it if/when NSAID doesn't work.
It doesn't seem to be a stroke, since something surely would have shown on the tests, but I won't rule it out. I don't feel myself today, I mean besides the numbness that is persisting. But I think it will run it's course as I am starting to believe this definitely goes with what you said about the pattern changing with your migraines. Strange that no one can discover a cure for this or that, and they just move onto something else. What I hear, even though they don't say it, is we can't help you, just go live with it.
We all have to do that with so many issues it makes me wonder why so much money is blown on things that are less important than people's health