The main duct is called the common bile duct. It is  common to the liver, gallbladder and farther down line, to the  pancreas as well. on the left side of your liver   It is on the right side of your body.
According to the article linked in the related links section below: A cold is contagious for at least a day before you come down with the symptoms. During that time you may be transmitting the cold virus to all of your buddies and co-workers even when you're feeling fine. Once you come down with the symptoms, a cold is contagious until the last of your symptoms go away.
It has an incubation period of about 12 - 48 hours, and can cause the person to be contagious during the incubation period and for as long as they shed virus (usually about three days after symptoms stop but sometimes up to two weeks).