Surely you have a family friend or friend or friend who you could explain the situation to and they would write you an order. This is happening for pretty much every person who is going in for surgery. They have to have a negative test before the surgery can proceed and they're getting tested w/ no symptoms.
You may be able to get a docs order via the Crush the Curve website, but not positive. Public Health is also using a standing order for anybody who calls in some areas.