It's definitely a good idea to get a professional opinion. I went on my own the first time (And every subsequent time) because I hadn't really discussed my concerns with people close to me, so I had no-one to take along.
It does help to take someone along if you feel anxious about the visit.
But don't worry about the doctor not "believing" you. They are there to listen to what you say, your symptoms, and make a professional recommendation.