No there are many places that do both tests, we tested at the Amatista Center which is next to the ADO terminal on 5th Ave. The cost for the antigen (US) test was ~$20 USD/pp if I remember. Very quick and painless, they email the results and you can also wait or return for a hard copy. The email includes a scan code which is also acceptable.
When we left last April we were never asked for our results, but that’s just due to the large number of people I’m sure…

If you are in the Cancun area they are located at Av. Kukulcan 8.5, Plaza Lagunas…


"Travel changes you. As you move through this life and this world you change things slightly, you leave marks behind, however small. And in return, life — and travel — leaves marks on you.”
-Anthony Bourdain