I'm going to tell my fiance that I am not planning on getting her anything for valentine's day
That sounds hurtful. Why don't you want to get her something for Valentine's day?
Well, I am not in love with her any more.
Telling your fiancee that you aren't getting them a valentines gift is not right, even if you don't love them. Uphold your relationship obligations or leave the relationship.
It's fine and I got other plans.
If you are not in love with your fiancee you should let her know, instead of stringing her along. Not receiving a gift is one thing, but leaving her alone altogether on Valentine's day because you feel different now is wrong.