I keep getting reoccuring sores on my tongue and on the roof of my mouth.I went to see my doctor and he said that they were cold sores,but that they weren't caused by the herpes virus.I asked if it was contagious and he said the risk was minimal if the other person was healthy.He prescribed valtrex.All the research I've done about herpes always refers to sores around the genitals or on the outside of the mouth.Could what i have be herpes contrary to what my doctor says?Should I get a second opinion(health department perhaps)?