This isn't uncommon. It can take quite a while for a piercing to heal thoroughly. It may do this off and on for a few months, so don't worry.
Ice it if it's swollen...otherwise you don't need to. As long as it's still an open sore or has a scab, clean it twice a day with hydrogen peroxide and put a dab of antibiotic cream on it after you do. For comfort, only wear the small studs while it's healing. Anything else will stretch the opening and make it take longer to heal.
As long as you're cleaning them twice a day, you can go swimming. Just put another dab of antibiotic cream on them before you leave (just to be sure.)