First Ultrasound

Hi Everyone!

So this is my first pregnancy and I of course am extremely anxious about everything and was hoping to get some advice. So I originally thought I was 8 weeks when I went for my first ultrasound but all that was visible to my doctor was a gestational sac and the yolk sac. She said it’s possible I’m a lot earlier (like around 4 weeks) than I initially thought but I know my calculations are right. Has this happened to anyone? I edited the ultrasound picture and I still can’t tell if there’s anything I should be seeing on there. Any help would be appreciated!