[F]I had my belly button pierced three days ago and now it is red, sore and slightly swollen under the top of the ball on the barbell. I had it pierced at a certified beauticians by a qualified piercer and I have been cleaning it to their recommendations. I don't know whether the condition of my piercing is normal or a sign of infection. If it is infected, How do I heal it to its best? :confused:

To be on the safe side, go back and have it checked out by the piercer. It is possible that it's healing normally but I'd check to make sure that it's not infected or that you are not allergic to the stud n barbell used.

Thank you Millerquest for your advice. However at this moment in time I am unable to visit the piercer because you can only visit by appointment and I am unable to make one within the next three weeks. This is the reason for my previous question.

But your input is definitely something which I will take into account if no more advice is given.

Does anybody else know of any treatments?

No you are assuming you have to make an appointment first, and second assuming they will not just check it.
You call them and ask them what time tomorrow can I come by for you to check this. If they say in three weeks, you report them to the health department, and the licensing department for poor business practice.

Thank you for your input.

After such a short space of time it's expected that it will be a little tender. You should try and clean it with a sea salt solution (spray the solution onto the piercing so you don't accidentally knock it) and if you're still worried, go back and see your piercer about it. They should be able to advise you on your piercing and the right course of action.