And I will throw in my two cents:
If you go back to the Philippines to go to nursing school
, please be aware that it will be a four year program that you are going to need to go thru there, only two years if you complete it in the US.
With the fiance visa, you have three months to get married, or it becomes invalid..........you would need to be petitioned again, more than likely if the 90 days are up.
I suggest that you speak to an immigration attorney before you leave. More than likely, you will need to begin the immigration process again, and there may be issues since you came on one and then did not marry.
AS fas as exams, you will definitely need the NCLEX exam, and more than likely will also need to do the English exams by then. It has been in discussion not to wave them for any nurses coming over that would have been required to do them if applying for their own visa. Imagine that four years from now, it will be the law.