Is it wrong to want to upgrade my engagement ring?

When my fiancé proposed we didn’t have a lot of money we were struggling quite a bit so the ring is very modest. Since then we have been much more successful and make very good money and have a large savings. I want to say my engagement ring is very sentimental to me and I would never want to get rid of it. But it would also be nice to have a ring that I truly find beautiful and love and we can easily afford that now but couldn’t when we got engaged (4 years ago).

Now we are planning our wedding the only thing that put it on hold for so long was being so financially strapped. I feel guilty because he doesn’t know I been thinking about wanting a new ring. Is it wrong of me to want to upgrade my engagement ring?