Is campho phenique safe during pregnancy

Jade
I have had a cold sore for several days now... But today it was way worse, my whole bottom lip is basically a cold sore. I'm 22 weeks pregnant. My OB prescribed me valtrex but it has not worked so far, so she told me to use abreva... However, abreva is expensive so I was going to use campho phenique instead. Does anyone know if campho phenique is safe to use when pregnant on a cold sore? Has anyone used it and their baby had problems??