M.D.
First of all, I wouldn't bother taking your breast pump onto the plane in a carry-on. Pack it in your suitcase and check it. Your son will want to nurse on the plane, so you shouldn't need your pump. Try to nurse him during take offs and landings, so that he will be continuously swallowing and popping his ears. Give him a dose of infant Tylenol about an hour before you take off then again 3 hours into the flight (for landing, just in case). You really won't need much of anything. Maybe buy a new toy that he hasn't seen, diapers, wipes, nursing cover (if you choose). You will be shocked how the hum and constant movement of the airplane will lull him right to sleep. I've flown with my daughter twice, once at 4.5 months and once at 9 months, and she slept almost the ENTIRE time for all the flights (8 in all). I wish you well and hope this helps! Good luck. Oh, and be prepared for the "death" looks you will get as you board the plane. People automatically assume your baby will scream the entire time (which he won't, I promise), so just look at them and SMILE!