Goingmadttc speak to your doctor about it. There was a flight attendant on my last bus who was grounded as soon as she knew but she said it is more to do with extended periods of exposure to "cosmic radiation" and that normal flying, even business travellers going every week are ok.
I flew a lot last time, but horribly, after DS was born I developed quite a bad phobia of flying... Beware!! It is apparently a frequent phobia triggered by having a baby. It is really damaging to me as I live in Spain and my family and lots of friends live in England.
DH has got a sickness bug and I'm really worried about catching it and it causing miscarriage... tell me I'm being paranoid please!!