Can i travel with 3 month old baby for 13 hour flight plz help?

hi pple just wondering if i can take my 3 month old baby on 13 hour flight would that effect his health even thought he's healthy and i have him on lap seat because its really expensive now the airfare (royal jordanian) is about 2000 and its an emergency situation that i must travel now and is it ok to put him on a car seat in the airplane even though i have him as a lap seat . pple im not stingy lap seat cost ( 560 dollars ) any way so any sugestion please fast answers plesssssse