Agree. Always get a second, or third opinion.When I was 5-6 years old, my parents took me to a doctor because they noticed that something about my behaviour was 'off' and they were worried. I isolated myself, had a eating disorder and just didn't do what the other kids did. He told them it was because I was left-handed, I was just weird and that was the end of that. They should probably have gotten a second opinion.25 years later I was given an ASD diagnosis.
The advantage of being in a large hospital system is that you have a care team,...several doctors, nurses, therapists, pharmacists, etc. Everyone has some input, but also, a lot of questions get asked. There's a lot of critical thinking going on. So, even though the lead physician is ultimately responsible, he/she has a team around them questioning their every decision and even guiding him/her through the process.
If you are not in the hospital, but at an office, you and the physician are sort of isolated from that sort of interaction. So, yes, get another opinion.