Heart rate and cramps! Help

I’m 21 weeks and had a pretty decent cramp, kind of in my back, so I decided to listen to my Doppler to check on baby. As soon as I heard the heart beat it was 175! I listen OFTEN and it is never that high. Highest i see is 165 but it’s usually 145-155 every time. It did go back down relatively quickly, within a minute or maybe even just 30 seconds or less of me listening I’d say (you know how time feels slow when you’re worried) and afterwards I had no more cramps and have been feeling baby move a lot.

Is that concerning?

When I google it the first thing that comes up says heart rate increases during contractions but then on some forums people said it’s normal for it to go down not up?

The cramp happened about an hour and a half ago and now when I listen it’s a strong 150-155 so it’s not happened again that I know of and like it said, I haven’t had any more cramps.

Was it most likely Braxton Hicks?

I just need reassurance. Thank you