I had a stress echo at queens, ny hospital and, a, normal stress test at the mayo clinic. could two stress test in two years miss a blocked artery?

Unlikely: At your age, the likelyhood of the 2 tests missing a blocked artery is very low. Under other circumstances, it is still possilbe for the tests not to pick up a blockage. The most definitive test is an angiogram which is not indicated at your age with negative non invasive tests.

Not likely: 25 yo with anxiety and two negative stress tests, should concentrate on anxiety and not chest pain.