Congratulations on your baby girl!
It’s totally normal to feel unsure about a name right after birth, sometimes it takes a little while for the name to “settle” and start feeling natural. [name_f]Lucy[/name_f] is classic, sweet, and timeless, and often that initial strangeness fades as you get used to calling her by it.
If it still doesn’t feel quite right, you could try using a nickname like [name_f]Lou[/name_f], experimenting with her middle name, or even trying out a few other names you like to see if anything clicks. Sometimes it just takes a bit of time for the name to feel like her.