Take an objective, well-lit photograph of your piercing right away to establish a visual baseline. Compare the visible length of the barbell post against that picture every week. If you notice the skin bridge thinning, the holes pulling toward one another, or the metal becoming visible through translucent skin, visit an established studio for a professional piercer consultation.
Prioritize your skin over saving a failing piercing. Removing a migrating ring early preserves the structural integrity of your navel, avoids painful tearing, and keeps the door open for a safe, successful repiercing down the road.