Lost friendship over my SO

Should I feel bad that I lost someone that I thought was my bestfriend basically over what I'm thinking my relationship. From what I'm being told she supposedly had a crush on my fiancé before he decided to sweep me off my feet. He says its because she's probably jealous & I honestly feel the same because whenever I'd mention him she'd change the Convo, she also gave us a dirty look once he announced during a get together that we were engaged. Should I be upset? Had this happened to anyone else before? She blows me off & ignores me now that I'm we're living together.