Upvote:4
should I be wary of the connection time in case something goes wrong?
No.
You need to show your test at check-in before boarding the first leg of your flight. Then you get your boarding passes and you are all set. There is no need to retest even if you miss your connection.
Test sample must be taken 3 days before departure (not arrival).
https://www.cdc.gov/coronavirus/2019-ncov/travelers/testing-international-air-travelers.html