well theres rules bt rules change for each and every airlines .as far as for ur travel sector preg in 7th mnth cnt be done as its nt safe foe baby and mother because difference in airpressure......so u can have a ban if ur travelling in ur 7th mnth nd above onwards....so chck widd airlines r travel agency for eny persons going in ur date enywyas u cn meet enyone in airport too..nd yes bfore travellinbg have doctors certificate stating ur fit for traveling here it willnt be required bt u shud have it....i had noone asked me abt certificate.