Question for those who use Dopplers

I’m 12 weeks 5 days. Is it normal that most times when I find my baby’s heartbeat it’s going good for about 30 seconds and then fades away and I have to find it again? Also for the last few times I used Doppler (every other day) I have found baby in the same general area and today I had to search more for him. It’s my first time having an at home Doppler and I can totally see why some people find them more of a hassle than good now lol Just trying to see if it’s normal. Hehe