dream interpritation please?

Question

im engaged but suddenly i keep having dreams that i am marrying my ex instead of my fiance. or ill have dreams that my fiance is cheating on me or that we are getting divorced after only a few years. im rediculously happy with my fiance (and im not just saying that, i really and truely am very happy), so why the hell am i haveing these dreams. they crept up out of nowhere. weve been engaged since december and these dreams started exactly one week ago. and the night before they started i had a dream that my fiance and i got married and were living the exact lifestyle we wanted....so why all the crazy *** dreams about my ex and junk latley?

this will be my first marraige, i was never married before.