That could be white blood cells trying to heal the piercing. It doesn't necessarily mean it's infected. Because your tongue produces saliva, it cannot produce a scab while healing so the white stuff actually sits around the top or bottom of the piercing and you just have to wipe it off. It isn't a big deal really. Everyone's so quick to say it's an infection when it's a normal part of the healing process. Don't worry, it has to happen for your piercing to fully heal, you should be fine.