I always have mild panic issues when I go to any doctor. Just this week I had my yearly visit with my OBGYN and had to talk myself out of panic mode while I waited for her in the room. I don't know why that is.
Perhaps it is fear because I know that some aspects of my health are out of my control...there could be something wrong with my body of which I am unaware and cannot do anything about. I think I may be a tad bit claustrophobic and feel ultra vulnerable sitting there naked and clad only in a big napkin. Also, I know part of it for me is fear that my IBS will act up while I'm mid examination. Whatever the cause, I has happened to me and continuously happens to me.
My heart doesn't race though. In fact, the doc told me I have a very low resting heart rate which means I have a well exercised heart. I was floored because to me it felt like my pulse was racing, so go figure. I get the light headed feeling, the feeling of being out of control, hot and cold flashes, sweaty palms, etc. It tends to go away once the doc comes in and I am distracted by talking with him/her.
Long story short, you're totally normal I think in this regard. I know people who dont' suffer from anxiety that freak about going to the doctor. Some to the point where they cannot go alone. It's scary stuff.