Yeah, it's best to have autoclaved jewelry in piercings that new. If it's from a jewelry shop people probably touched it with unclean hands before putting it in the package.
How's it doing now? I can imagine it's pretty annoying; I've knocked my navel several times even with a curved barbell in! Having a navel piercing definitely makes you aware of all the movement in that area and how much stuff touches it.
I have 1/2" lobes and 11 piercings: left helix x2, both conches, both nostrils, septum, navel, and VCH.
My lobes are small but I know a lot about stretching and how to do it safely, so message me if you have any questions!