I would call the insurance company, verify with the doctor's office, and then call the insurance company again to talk to a different person.
Just because the insurance company verbally tells you, the doctor is participating, doesn't mean it's so. If you really want to be covered, try to get it in writing.
I speak from personal experience, we needed to find a new pediatric urologist and NJ BCBS gave us a huge runaround as far as helping us find participating doctors. It also turned out that a doctor from CHOP in Philadelphia was covered in PA but not in NJ where we live. Confusing. We got differing info from both the doctors office and the insurance.
But the best one was the book of participating doctors. One doctor that we know personally was in JAIL for medicaid fraud was still listed as participating!