teething can be quite painful. the tooth pushing through is creating a wound. do you remember your wisdom teeth? the tooth does not just push up quickly. the gum and cheek around the tooth can become very sensitive and swollen esp. with the back teeth. low grade fever often accompanies teething as well. it's completely normal. the only time i would be alarmed is if the area had white patches, or seemed to take to long to come in. a high temp as well could signal infection. just keep an eye on it.
try frozen bite size pieces of bananas to help. i never use orajel, though i do have a friend who loves it.