The piercing will start to shrink almost right away, but the piercing will not close completely for a few hours till it shrinks to a point where it can start to close on it's own. Be careful when replacing the jewellery do so after a shower where the tissue is moist and the jewellery can be replaced without having to force it into the piercing. If it's too snug go see your local body piercer to have the piercing tapered open to replace the jewellery.
If you want to wear a regular navel ring in your inverse piercing, turn the navel ring upside-down, so that the larger gem is in the navel, and the smaller gem is below.
it is a plastic piece you put in to retain your navel piercing
Well it looks like a navel piercing with a navel gem barbell or a captive bead ring in it.
With tweezers or something that can grip the piercing.
barbell is better because if you get a ring it rotates around and the bacteria gets inside the piercing also if you get it pierced with a ring you might have difficulty putting a barbell in later
Not long at all, piercings don't heal in a month especially the navel piercing, it takes from 3 to 6 months for a good light heal, but is far from healed and seasoned to handle having the jewellery out for long.
Ultimately the less material sticking out of the piercing the better. See in the early days of navel piercing, they were all done with rings however this meant the piercing could be irritated by the excessive amount of material exiting from the piercing. Now with the advent of purpose designed body jewellery a properly sized and fitted navel gem means the piercing has less material that can snag or hang up on clothing. This allows the piercing to heal without the irritation seen in ring navel piercings. The navel should be visualized as a nest, the navel gem "gem" should be considered as the egg in the nest and should be centered to hang in the middle of the navel. The object is to draw attention to the whole package not just the gem but the navel and waist line as a complete package. The object is to highlight the figure of the client, this is where an experienced eye and the knowledgeable skill of a professional body piercer comes into play.
Every person is different. A month is not long at all, and especially since it's a navel piercing, it will start to knit shut immediately. You could probably still get the jewelry in (after an hour or a few hours), but you'd be causing damage and asking for an infection.
Years ago that was your only option, however now you can have the piercing done with a jewelled navel banana bell (basicly a bent barbell with a facetted stone in the navel ball).
Yes, and they recomend you not to cause the eyebrow ring may sink into your naval. they recomend you to use belly button rings instead.
It depends on your body. Some people stay open and just shrink. Other people's navel could close completely in a matter of minutes.
Body piercings aren't meant to be. Your body probably isn't agreeing with what you're doing to it.