Home Doppler.

Hello. I need a question answered. So I brought a home Doppler the week I found out I was pregnant though I was only 3 weeks and 2 days. I knew I wouldn’t be able to hear the heartbeat, but I waited until I was 9 weeks and 2 days to hear my little ones heartbeat through the home Doppler. Well, I use it weekly now. Not for fun, but for reassurance. I have heard not to use it for reassurance to only use it to fun. Why does people say to not use it for reassurance but rather use it for fun? It is nice and fun to listen to it, but I mainly do it to make sure the baby’s heartbeat is still going. I’ve seen so many post on here and also Facebook that the baby’s heartbeat stopped at 10-20 weeks of pregnancy even 25 weeks. I am scared as ever now because of it. Is it okay for me to use that way? Or should I just stop?