I noticed yesterday that my 5 year old son had a blister looking bump on his gum on the bottom front. I made a dental appointment but can not get in any sooner than the 14th. Now today he is complaining of sore throat and has a fever. I took another look at the blister and when I softly touched it, a yellowish liquid came out followed by some blood, but he says it isn't too painful. Could the blister, sore throat, and fever be related? If so, what is it and should I take him to emerg since I cannot get into the dentist until next week? Please help!