My appologies as this isn't strictly "etiquette" - I just find that this board offers the best advice

So, my fiance got me an AMAZING engagement ring. This ring also happens to come with a matching wedding band. The problem is, I don't really like the band and the ring is so unique on its own, I kinda don't want to have another band.
Do you think it is ok if I don't have a wedding band and just use the engagement ring in the ceremony? My fiance doesn't care, but both of our mothers are horrified. I'm not sure how I feel. I really don't like the matching band, but I worry that I'll regret not having a "real" wedding ring....
UGG!!
(to help, I've added pictures of the engagement ring and the ring with the wedding band addition)