You don't have to remove it unless it gets uncomfortable . I'm 14weeks and still have mine with no problems I do plan to buy the maternity ring tho just because there longer and flexible! My dr said ur belly rung should be removed if it gets infected/irritated or just uncomfortable for you. Not much help but might be lol sorry!
I took my belly ring out around 12 weeks for similar reasons. Mine was gettin' uncomfortable, and hurting, and It turned a lil' red, like It was gettin' Infected (had my belly pierced for 3 years with no problems). So I decided to take It out and my belly button felt a lot better. You don't necessarily have to remove It If you don't want to, you can buy Maternity Rings, but If It continues to hurt, I would take It out and ask your doctor about the pains If they continue, could be because of your belly stretchin' but I'm not too sure. Sorry I'm not much help.