I recently got my belly button pierced, and the third day I had it I noticed it started getting very red and painful. It was indeed a mild infection.
The skin around it had gotten very stiff and irritated. I put a hot compress on it 1-2 times a day and cleaned it very well with Saline Wound Wash (which you can purchase at CVS or other drug stores).
I would also apply a small amount of pressure in between both openings so that anything that was in there could escape. If anything did escape I would remove it with a Q-tip soaking in Saline.
My belly button started to peel around the piercing openings but I didn’t worry too much about it. Within a few days my belly button ring was noticeably getting better.
All I did was keep an eye on it and made sure it was getting better with everything I was doing. If it hadn’t gotten better I would have gone to the doctor and asked for and antibiotic.
I don’t know how true this is, but I heard if you were to take the piercing out while it was infected you could develop and abscess and need surgery. I certainly did not that want happening, so I just did all I could to heal my mild infection.
Just know if you are deciding to get your belly button pierced that you MUST take care of it. NO LAZINESS! I cleaned my belly button very well 3 or 4 times a day before it got infected, and still it did get infected.
Even if you are very responsible there is still a risk of infection. But if you are responsible and a risk taker then it’s all worth it in the end =)