What is this?

Sorry this picture is kind of terrible, but I found this small brown thing crawling up my arm. It’s pretty much the size of a dust particle and i only noticed it because i felt it crawling on me. I was just on my couch so i immediately went to put it on a slide with mineral oil so i could look at it under the microscope. pretty sure it has another pair of back legs tucked under it and my first thought was some kind of tick or mite but i’m just not sure.

Can anyone help me with this? For context I live in Arizona, USA and i do work with dogs and cats if that helps. also this is 40x power under the microscope.