Super Tired and Hungry, late AF

I'd say the majority of the time, I know when I'm coming on, even if I'm late. But there been a few times since November where I'm been 40-50 days late and I feel the exact same as I do now. For the last 3 days I've been awake probably a total of 12 hours, and I'm still trying to force myself to stay awake! I'm also really hungry but feel full because I've just eaten. I'll continue feeling like this until my period comes. Last time I thought I was pregnant, but it wasn't and doubt I am this time. Doctors don't know what to do and they have no idea why my periods are all over the place. I'm autistic, so I'm wondering if it could possibly have something to do with the way my brain is. If I wasn't already classed as disabled this would definitely stop me from doing everyday things, so without any diagnosis this could affect peoples lives other than my own. Anyone else like this?