Airport security

Kristen • First time mommy!!! So excited to meet this little blessing at the end of Nov.
Hey ladies!!! I need some advice!!! I will be a little over 17 weeks by the time my husband and I go on our first trip since I got preganant!! 
  I am nervous to go through that scanner at security!!! I don't really know what to do or how to let them know I'm not comfortable going through there!!! Can any of you ladies help me out and let me know how your traveling went!!! Thank you so much!!!