things to bring with you through airport security before an overnight flight (as a person with breasts and discharge):
1) bralette. I'm a 36 HH and a torrid 2 fits my boobs fine and provides enough support for sitting on a plane without hitting my seatmates in the face with my boobs.
2) clean underwear to ameliorate chafing/swamp crotch mid flight
3) empty water bottle to fill on the other side
4) toothbrush (and travel toothpaste)
5) chap stick

@Maenad thank you for this sizing info. Imma get my 36H self to torrid