Heart rate at my scan

So when the sono tech got the heart beat the first time it was in the 286 which of course didn’t seems right so the second time we got it it was normal 152 has anyone else had this happen she seems to think it was the echo waves possibly I am just worried could it have been 2 heart beats she picked up at once?? Please no rude comments this is my 3rd but it’s never happened before to me🤔