Sores in my throat.. No diagnosis???

Not really a pregnancy thing but I'm just curious if it's acceptable for a Dr to just not diagnose you?? I have 2 sore looking things in my thoat and went to my regular dr and she tested me for strep.. Mumbled something about ulcers.. Viruses.. And sent me home. They called and said it's not strep and just said it should go away.. I'm mostly just curious what this is and they didn't seem to know or care or want to give me any explanation?? Is this normal and I should just accept it and ignore the sores or is she just being lazy?