New piercing

I recently just got my belly pierced on Friday it will be a week since I got it done. But I need to change it . I’m going to see my bf this weekend and he’s locked up so I need to pass through metal detectors if I tell them I have a piercing they will make me take it out so I want to by a plastic bar so the metal detector won’t ring. Any advice how I should do it so it won’t really hurt. ( my piercing is fine it hasn’t hurt me since I got it I’ve been cleaning it good )