Strep throat is bacterial and not viral. If you have it, you'll run a fever (mine gets as high as 103) have swollen lymph nodes and tonsils and usually white or yellow pus like spots on the back of your throat/tonsils.
According to WebMD, if your sore throat is accompanied by runny/stuffy nose and a cough, it's probably a cold/virus. Then the sore throat is probably caused by drainage. If you're worried go see your doctor. They'll do a quit strep culture; it takes about five minutes or less if you're seriously infected. I speak from experience.

IF it's strep, they'll give you an antibiotic, otherwise the cold will have to run its course.