Worry wart

Has anyone looked at their ultrasound pictures over and over and then thought it looked like a white hole in your uterus? This may sound like a stupid question but I knew someone who had this and lost their baby im very worried I've had two ultrasounds with me doctor and one from a special early gender clinic and no one said anything is concerning at all is there supposed to be white hole looking things all around your uterus? Again I might sound stupid asking but I'm worried and would just like some piece of mind. I'm 15 weeks 1 day pregnant