Can people refer to me as an MD in my recommendation letter if I have already passed my professional exam but my degree is still in process?
I am struggling to understand exactly the position you are applying for and don't know much about the medical field, but would expect your references to refer to you on a first name basis in the letter. This seems even more likely in the case where the degree status is in flux/unclear. At some point in the letter it should probably say something like


  Luis has completed their MPSS at University of Mexico, completed the internship year, and passed their professional exam. They have completed all the requirements for their doctorate in medicine and will be receiving the MD degree at the graduation ceremony in May.