Can ultrasound tech mistake the heartbeat ?

Is it possible to mistake the mothers heartbeat for the baby’s heartbeat during a transvaginal ultrasound?

I currently think I am having a miscarriage. 😢 I’m supposed to be 6wks 3d and I started spotting this morning and went straight to the er. They took a bunch of blood and checked my cervix and the amount of blood I was having. She said my cervix is still closed, but it was more than just spotting and didn’t look good. I’ve already realized what is happening, but I can’t help but have a tiniest bit of hope. After waiting for what felt like 10 years they finally took me for an ultrasound. The tech told me my hcg level was 316 and that the baby definitely wasn’t 6 weeks yet. That’s when I realized .😭💔 the tech didn’t tell how far along I measured either. The weird part is (and I probably sound dumb asking this) she stopped during the ultrasound and informed me If I heard any noises that is just blood running over my ovaries. During that time I did hear some swooshing then I heard a loud heartbeat while she was moving around in there. I wish it was the baby’s heartbeat.