At home Doppler….

I’m 12 weeks and can’t find baby’s heartbeat😢 with an at home Doppler I’ve been trying to find it since I was 7 weeks had 3 ultrasounds at 6+1, 7+5 and 9+5 and baby has a heartbeat all 3 times❤️💓 I found my son’s heartbeat at 16/17 weeks so maybe I need to wait until then?? What’s the chances of having a miscarriage after seeing/hearing a heartbeat 3 different times?