Is my (M30) Gf (F26) negging ? What do you guys think ?

My(M30) girlfriend(F26) compliments me in a weird way, which feels like a shes trying to not let me be too happy about the compliment (but isn't necessarily a back handed compliment either). Examples :

\- You're the Best Boyfriend **I could ever get.**

\- You're the most handsome guy in the world **to me**.

Feels odd, not bad just odd.

Before you tell me to ask her, I did and she just avoids the subject and implies something like she's never letting me go.

Why not just say "you're the best boyfriend" ?

Is this negging ?