Hello and welcome to JustAnswer,
That's an impossible one to anwer without hands on and eyes on you. could be a strange type of hernia, and if it is, it would need to be fixed with surgery. Abdominal problems can be so complex that it is safe to say that if you have a baseball sized swelling in your right lower abdomen that you need a doctor to press on it, examine it, and figure it out. If it is a Spigellian Hernia (hernia in lateral abdominal wall), these can be dangerous if not fixed. Other than that I can not imagine what would pop up so suddenly and cause, apparently, no symptoms.
I did answer your question.... can you see my response above yours?