help! im freaking out 6w u/s

Littlesmommy521

so i went yesterday for my 6w u/s..by my LMP i should have been 6w3d yesterday, they did an internal u/s and only saw the yolk sac. she said she *might* have seen what could be a baby starting to form but she couldnt say for sure. so i have to go back in 2 weeks for another ultrasound. .. is this normal to only see a yolk sac at 6w? she asked if i could be not as far along as i thought but i dont think i am, unless i o'ed super late. any input is appreciated, thanks!