14 weeks rapid heart rate

Jane

I’m 14w4d and for the past few days I will randomly feel my heart start pounding/racing. I don’t even have to be doing something other than standing. I’ll just be standing while I’m at work talking to a patient and then within minutes my heart is racing and I feel like if I don’t sit I’m going to pass out or throw up. Does anyone know what could be causing this? Or how I can prevent/stop it?