That's great! Gracias for the update.
If so, good. I remember when Mrs. T-B. was quite pregnant with the future Mini-Bone, and we'd had a traumatic trip back with hosed flight arrangements, and the female CBP agent (in a foul mood) gave us lip. I was one step away from telling her that Mrs. T-B. held a future U.S. citizen who would be more American than was she, the CBP agent requesting that the shift supervisor join us.
Regarding stress, avoid going aysheep beforehand without reason, but be prepared to use the magic words that resolve many situations everywhere: "May we speak with your supervisor now, please?"