Confused

Nikki Marie
So this is my third baby and I pretty much know how this goes and according to my lmp I should be 6wks 5 days I went to the doctor yesterday and had my first ultrasound but what we saw was only a yolk sac to which she said meant I'm only abut 5 weeks she couldn't even see a fetal pole...I'm worrying myself to death thinking something is wrong with my last two pregnancy my due dates were dead on with my lmp...anyone else experience this?