NST question

How long did your NST last? I've got one scheduled on Tues, but I have an appt at the spa later in the day. The drive between places is kinda far, but I'm so close to my due date I refuse to reschedule the spa appt lol. I will get a massage before this kid is born. Anyways how long did y'all's test last? Anything I can do to make it go quicker?