Plane travel at 25-28 weeks with twins?

Nicole • Married to the most amazing man on 9.28.14, had identical twin girls on 3.14.16, now expecting number 3 in May!
I'm 13 weeks with mono/di twins and am unsure of travel procedures for twins... i know that flying overseas with one baby is fine until 32 weeks. my husband and I are stationed in hawaii but want to fly to NC for Christmas to see family. That shouldn't be an issue right? One thing that concerns me is my u/s technician told me yesterday I have to come to the hospital weekly for fluid checks and for twin to twin transfusion syndrome checks.