NT scan

hi guys .. at my last appointment, I asked my OB if I can get a NT scan and she agreed. After that appointment, I received no call to schedule it and I was kinda relieved that I'm not getting it because I would freak out at everything.But today I received a call and they have scheduled me for it with a maternal fetal medicine dr and now I'm worried about it . I'm just feeling that it would bring unnecessary worries when I need to relax .I'm a chronic worrier .should I cancel it or just go for it .I just feel thar the more we explore into mother nature the more unnecessary problems we get .plz give me your opinions. did you have it and how everything went for you. I'm 35 yo.this will be my 3rd baby .