I read a lot of things here but couldn’t figure out a clear and safe answer to my own question. Thank you for your help!
I will go in 3 days to the US, where I will stay exactly for 90 days (I have an ESTA). I recently made the mistake to buy a flight to go home with a date that happens to be approximately 3 weeks after the date I am allowed to stay in the US.
Since I can’t cancel that flight and would like to avoid to lose money for nothing and buy a new flight on top of it, I thought I could go to Mexico for these 3 weeks after my 90 days, and then come back by plane to New York in order to catch my flight home on the same day. Which means I would have to pick up my luggage and therefore cross the border to do the check-in for the flight home.
Will I be in trouble at the border (or already at Mexico airport) because it would mean exceeding my stay, even though it’s just for a layover/stopover and I have the proof I’m leaving the country on the same day?
Also, since Mexico doesn’t count as a foreign country, does that mean I’m exceeding way more than 1 day, but in fact 3 weeks of overstay?
Thank you very much for your help!