I fly for my job average 4/9 short hauls a week and some long hauls a few times a year and there is conflicting info about the subject ..
I think you will be fine if you fly once or a few times and some people fly a lot till they are late in PG ..4 Doctors and my accupunturist told me not to fly or fly as less as posible in the firts trimester ..something to do with the altitute and internal organs , while most people are ok flying some sturdiest are placed on ground as soon as they are pregnant ..based on studies ,flight attendants are 50 percent more at risk of miscarriage.
I personally decided to stop my mad flying in my first 3 months of PG , i miscarried last year and i took around 25 flights the firts months of PG , ill never know if that caused it but i will not fly as much this time so canceled 70 percent of my flying ..but I am older and might be my last chance of being a mom so i decided to take all precautions ..
I really think is a personal choice and done in moderation is ok.
A