That sounds like some kind of infection. You need to see your doctor and seek treatment.
Probably an infection, you probably want to go to the doctor soon to help. It might infect the baby if you wait too long.
It is definitely an infection. The belly button can hold a lot of gunk and lint, and can get infected easily. It WON'T affect your baby so don't worry about that! It is not connected to the baby. The only issue is if it gets very bad, and you can then get an infection as the body tries to fight it off, and get a temperature. THAT can affect the baby. So go get it looked at and no doubt they will show you how to clean it and give you some cream to use.