First Ultrasound, who should be there?

First time mommy! I’m scared, not sure what to expect. I have not told anyone yet but my fiancé and a few close friends. I want to tell my mother on Mother’s Day.

My first ultrasound is on May 9, and one of my close friends will like to be there. I feel that since it’s my first ultrasound, it should just be a moment for my fiancé and I. How do I kindly decline?