Can't find my immunization records? Need them for a job. What to do?

Okay so I get a new job today. I was aware that I would have to do a background check but I had no idea I would need a physical too. In order for me to get my drug testing and physical I need to bring my immunization records...One problem, I can't locate them anywhere. I'm currently uninsured would my last health insurance provider have these records?