I am a student getting ready to start the fourth semester of my ADN program. I'm not sure exactly what your school requirements are, but I would recommend completing all other prerequisites and co-requisites before beginning the nursing program. I still had three co-requisite classes to take after I started the program. And though they were not hard classes, I found myself many times wishing that I could spend the time required for those "non-nursing" classes studying my nursing material. Additionally, the material you learn in A&P is necessary for nursing. I feel it would be a disadvantage to not already have that knowledge. I do know at least one person, though, who took A&P II while already in the program, and she's still around, so... These, of course, are just my opinions, and I wish you the best!