Suggest Treatment For Painful Sores In Mouth

Hi, today well tonight I have noticed what looks to be a sore in my mouth. Its on the side wall of my throat next to the uvula or as others would refer to it as the hangy ball thing in the back of your mouth. I would like to now if I should have any worries. This is the first time something like this has ever happened. I am 20 year old female not very sexually active maybe 5 times a year at that maybe I have never given oral sex and I dont kiss anyone besides my nephew when he is leaving to go home. He has had a recent outbreak of sores in his mouth and several other times since he was younger, he is now 5 years old nd doesnt have any sores at the moment that I know of. Could I have gotten the sore possibly from him from just bacteria and saliva transfer being that we share a cup of juice here and there. The sore doesnt really hurt but in the area the little pain thats there sort of resembles the pain of a sore throat but not as intense. Please get back to me I am a bit worried and would like to know if I should take any further notices and go to a doctor or something.