Phenergan or Benadryl

Stacy
I have a prescription for Phenergan for when I have migraines. It helps a ton with nausea and sleeping. In having so much nausea right now and I'm needing relief. I'm 4w5d. My doctor says it's safe to take but I'm so apprehensive. Has anyone else taken either or both during early pregnancy?  Thank you I advance!