I flew to NZ (3+hrs) between 6 & 7.5wks, which I was told was fine. Of course I did watch what I ate though, wasn't game to go to any buffets. I heard that if your in the 3rd trimester it can be an issue. :-)

To prevent DVT, you should move around regularly, including raising your heels & lowering them, to get more circulation going. When I flew to USA (14hrs), when not pg, I also heard from a work colleague about taking an aspirin a day for a few days b4 you fly, helps thin the blood (to help prevent clots, eg: Deep Vein Thrombosis). But I should've probably chkd with my Dr first. At my work, there is always someone travelling o/seas.