Is it safe to fly when pregnant?

Hi. I need some advice please.

Me and my SO are ready TTC. We have a holiday booked for mid September which is a four hour flight away. I was just wondering if I get pregnant before then is it safe/okay for me to travel on a plane (as I know the first 3 months is a risky period etc.)

I just want some advice or experiences that people had who were pregnant whilst flying. Thanks.