It's possible that you may have more than one type. There are dozens of types/kinds, and they can present differently, and/or combine with other kinds of migraines or other kinds of headaches. I say this from experience.

I have an uncommon one called 'chronic tension type/migraine complex -- sudden onset'. It can present as a tension headache crawling up the back of my neck, as a migraine on my left side in the back, on the left on the side, in my shoulder/back, or behind my left eye. Maybe one time out of ten, it manifests on the right side. I've never experienced an aura from any of them. Since it's a complex of migraine and tension headaches, and different meds are used to treat each type (and don't work on the other) sometimes it's a guessing game of which type (or both) to treat. Sometimes they fool me and I guess wrong. The strangest thing of all is that this was all brought on by a virus. I got a common cold (rhinovirus) that somehow re-activated the dormant epstein-barr virus (mononucleosis) I had as a teen. This is actually a documented type of headache, but it took a migraine specialist to recognize it.

What I'm getting at is that these crazy things can come out of nowhere without any rhyme or reason.

If I may make a suggestion, try some homework/research about kinds of headaches & migraines. You might come across something that clicks (fits the symptoms you're experiencing).

Doc