Sometimes you can have swollen nodes if you've been exposed to a virus or something. Your immune system responds (hence the swelling) but because it's doing what it's designed to do, you don't get sick. But if it continues beyond a few days you need to get it checked out because it can sometimes be a sign of a hidden infection in your body. Glands that feel hard or rubbery or don't go down after a week or two need to be checked out urgently, especially if you are also feeling fatigued, having night sweats or weightloss. Usually though the swelling goes down and you can congratulate yourself on having an effective immune system!