The government has passed laws allowing some preventative care services at no charge. Check your insurance policy coverage and additional details at CDC.gov. You can schedule a preventative care or "wellness" visit, but remember that if your discussion goes outside the boundaries of a wellness visit and you could be charged.
If the doctor wants to schedule a test or procedure, you could do any of the following:
Ask the doctor for a good faith estimate. Then share it with competing providers to see if they can give you a lower price.
See if the service is included in the provider's shoppable services site
Doctor offices, urgent cares, imaging centers and other such centers owned by hospitals may add an unexpected hospital "facility fee" to the bill. This article from PIRG tells more.