I can’t find my baby heartbeat 😳😳😭

My doctor confirmed a heartbeat at 7 weeks 1 day and again at 8 weeks 6 days via ultrasounds her heart rate was 170...With covid 19 going on I knew I wouldn’t be able to go to the doctor nearly as much so I bought a Doppler. I couldn’t find the heartbeat at 10 weeks 5 days so I got scared and went to the doctor she was able to find the heartbeat WITH A DOPPLER at 11 weeks 2 days she said it was strong and steady at 163...At 12 weeks I tried to find it myself so my husband could hear and I found nothing now I’m now 13 weeks 1 day and wanted to try it again to ease my brain and I still can’t find it. My next appointment isn’t until 20 weeks... Am I just overthinking things or do you guys think something could be wrong... I still feel pregnant and I’m still getting bigger... I’m just scared.