How to find out if I'm being bad mouthed?

I've been applying for work with a new company in the medical industry. I'm trained in medical coding but I ended up working in a pharmacy, I needed the job and money 6 years ago. Now I'm ready to move on and I think my boss is bad mouthing me to anyone checking my work status. That or not a single person has called after sending 30+ apps w/resume.

usa jobs
usa jobs resume
usa hotel jobs
usajobs
usa jobs federal government
usa job in ksa
usa jobs
usa jobs login
usa jobs gov
usajobs.gov
www.usajobs.gov
usajobs.com
usajobs
usajobs.gov official