According to regular procedures, your doc should have tested your TB first and then checked X-ray if it were positive. This means, that people with negative TB test result don't have to take chest X-ray.
So your doc did wrong because he just went ahead by his habit for Asians.
USCIS won't care the final medical result but only a report that your health situation is OK as a new immigrant. So your doc's report is critically important. Follow his orders and help him complete the report.
If you still feel not sedated, try to re-exam it again by other docs. But I am afraid they will check your chest with X-rays directly if you have already done the skin test because skin test should not be processed frequently. Medics has the regulation.