First gyno app.

So I'm 17 and my doctor is sending me to see a gyno as I have never had my period before. I had ultrasound about 5 months ago but all was clear I had an appointment with her today and she really wants me to have full blood work done but the problem is they will get me to have a needle I will have to be knocked out becuase I can't do it due to previous experiences. So what should expect at this gyno appointment next week. I'm so scared and nervous about it all. Please help x