20 weeks

I am 20 weeks today and I was wondering is it bad to use a Doppler everyday? My pregnancy is a high risk and even though I have been having ultrasounds every 3 weeks since I was 4 weeks. I still worry and use the Doppler everyday or every other day. I am now having an ultrasound once a week because I had my first daughter at 26 weeks so they are checking my cervix weekly. But I still worry and want to hear my baby’s heart beat everyday. I feel him moving every once in a while but when I don’t I use my Doppler and I am so relieved when I hear his heartbeat. I always forget to ask my doctor if it’s ok to use it a lot. I have an appointment in 6 days for a level 2 ultrasound so I will def ask. But I just wanted to know how often do y’all use your Doppler if you have one.