Ask him or her. Your best bet is always to level with your physician. Ask dirctly and if you are not satisfied you can also ask would you recommend I see somebody else. We don't always have all the answers. There can be many options.
Second opinion. Fibromyalgia is a relatively common disorder so it is unlikely that your doctor does not know about it. You can always get a second opinion if you are not getting better. If you are getting better, then no need. Don't worry what the doctor really knows; the medical community knows very little about fms as it is.
Talk With Them. There are many doctors who have a lot of experience in treating fibromyalgia. Some primary care have a special interest as well as some specialist, including rheumatologist, pain management, and physiatrist.