Serious question,

I went yesterday to get an ultrasound done on my liver cause the levels were high on my blood work. During the ultrasound I heard a heartbeat... I didn't think I was pregnant but now I'm freaking out because during an ultrasound you can't hear your own heartbeat. I took a pregnancy test back in June when I thought I might be because I gained a bunch of weight randomly in a short time period and was very nauseous and had a loss of appetite, but it came back negative. Any help or clarification? Thank you and please don't be rude I'm actually confused.