Time to get up and get dressed to go to my nst testing it always makes me nervous like they are…

Time to get up and get dressed to go to my nst testing it always makes me nervous like they are going to find something wrong but so far he's been perfect. My doctor felt he was measuring to small a couple weeks ago and at 37 weeks weighed 5.5 pounds from looking at the anatomy scan we had to get but everything else was perfectly fine. she said he might just be a small baby at 6-6.5 pounds at birth but she wants to continue having me come in twice a week to check his progress until he's born. I know he's doing fine it just freaks me out!