I am 26 weeks pregnant and got a cold sore in my lips. can i use abreva?

Herpes simplex: Abreva (docosanol), is a topical cream to treat cold sores caused by herpes simplex 1 virus. The fda has listed abreva as category b, meaning it does not cause fetal defects in pregnant animals but there is insufficient human data to approve the drug for use during pregnancy. By its chemical structure and topical use it would probably be safe, but nobody has evidence.