Nothing to worry about. I had that with my first..my fluid was low, I had no sign of going in labor and with that test they wanted to make sure the baby is doing fine.
I just had a stress test done on Monday because I was having contractions, my baby dropped & pretty much quit moving & I just entered my 35th week. Turned out everything was fine, he was still moving but was just cramped and his movement was much softer so I was having a hard time feeling him. Before I went into my test, the nurse told me to drink orange juice & then do a 10 minute fetal kick count.
I wouldn't worry they don't move as much after 37 weeks...I just had my nst on Thurs morning and she only moved twice because she was sleeping!! But they said it was fine. I have another one Tues morning...if u want to get the baby moving drink something cold right before :)