Me personally, I would wait and take it in the fall after the program. I have been a MT for almost 7 years and just started nursing school, and from my experience, they are two very intense courses in different ways. In MT school, you will focus on the muscles and bones much more than in a regular anatomy class. In pre-nursing anatomy, you will need to know certain muscles origins, insertions, and actions, but in MT school you will need to know nearly all (because this will be your domain as a massage therapist). The skeletal system is roughly the same in both. In pre-nursing anatomy, you will focus a lot more on tissue types and identifying microscope slides (which you don't do in MT school) as well as covering more of the nervous system.
Personally, I think having been a massage therapist before going back to school to do nursing made the so-called "dreaded anatomy and physiology" A LOT easier to me. Then again, ever since the second day of MT school, I was fascinated by A&P. That's probably what made me want to jump into the medical field.
Anyways, you'll love MT school. Because you'll have to practice on each other, it can be stressful and the most relaxing, all at the same time. Good luck!