Don't worry Erick, It'll all work out! Matricula is fine. I used my passport. It was super quick. All I did was fill out a short form they handed me as I walked in, after I filled it out I returned it to the man in the front, then he handed me a number. I waited for my number to be called then they fingerprinted me, took my photographs and that was it! I was there for like fifteen minutes. I was really nervous because I thought the workers would treat me different, or I would feel odd and out of place, but it wasn't like that at all. I finally figured out I could care less about what others think, head up and keep moving forward!