advice on engagement ring

am i the asshole for being upset that my bf got me an engagement ring the complete OPPOSITE of what i wanted???? i wanted an oval stone with a gold band. i wear solid gold jewelry. he got me a square stone, silver band. like is this valid or??? he hasn’t proposed yet but he showed me the ring. i’d showed him before exactly the kind of rings i wanted. do i even tell him that i don’t like it? or what