Safe to fly at 12weeks?

Audrey • I'm a first time mum and baby will be due end of July! My husband and i are very very excited!
Anyone flew during their first trimester? Is it safe? This is my first pregnancy and i am worried and just want to play safe.
This trip is booked way before i know i'm pregnant. I will be 12weeks when i fly. Flight would be about 4 hours.