My girlfriend recently had her first cold sore appear on her lip on a Monday. It started to swell up and that day her friend gave her some sort of blue pill to treat it and she began to use ointment. Since she caught it at the very beginning the sore never opened up or scabbed over. The swelling went completely down by Friday and she just had small discoloration on her top lip. On Saturday she performed oral on me. I was under the impression if it wasn't an open sore then it wasn't contagious but after reading, I'm worried I might have contracted it genitally.