Doppler

I have a Doppler at home and I just used it td for reassurance and my baby started to kick hard / kick the Doppler. I’m assuming it finds it uncomfortable..

how long are Obgyn’s supposed to leave the Doppler on your baby’s heart? The last time I went she kept it there for about a minute or two but is that necessary.... I just don’t want her to leave it on my belly for so long if it’s making the baby uncomfortable