high baby heart rate

Roseanne
So yesterday and today baby has been moving softly and a little less but still above the guidelines, so I had an appointment at 1 and thought I'd just bring it up then.
 
At the appointment baby's heart rate was over 190 and it just kept hovering between 175-190. They put me on the NST and it still was 160-190 for 20 min.
 
I was sent to the hospital and it took me about 45 min to get there.
 
At the hospital the heart rate was normal, 140-160. They told me to drink more water and have a follow up appointment tomorrow.
 
Anyone else have a long stretch of high heart rate like that? What happened?
 
37+ weeks