I don't know, there's a chance you might get away with that, but I'm worried if you arrive to customs and they want to check you have all your documents (return tickets, money, travel insurance), and if they see you don't have travel insurance, they MIGHT refuse you entry, I don't know. Why do you not want insurance? It's only like $100/month or so, and it's way better than paying $2000/day for a hospital stay.