Is zovirax (acyclovir) safe during pregnancy my ob prescribed for me and im in a middle of a vaginal outbreak but i didn't take any single pill im 14 week pregnant

No adequate studies: Though there are no adequate or well-controlled studies on safety of zovirax (acyclovir) in pregnancy, some studies indicate no association with an increased risk of major birth defects when used in first trimester. Thus Acyclovir should be used during pregnancy only if the benefit justifies the potential risk to the fetus. Please keep in contact with your doctor for continuous care. Take care.

Zovirax oral: "US FDA pregnancy category B: Animal reproduction studies have failed to demonstrate a risk to the fetus and there are no adequate and well-controlled studies in pregnant women." per https://www.drugs.com/pregnancy/acyclovir.html. Thus it can be used if needs outweigh risks.