First ultrasound, dates off or bad sign??

Lindsay

Had my first ultrasound today thinking I was 7+1 based off my LMP (5/3). But doctor said it was more like 6+6 and my scan showed a gs measuring 3mm consistent with 5 weeks and that’s all :-( he started throwing the miscarriage word around and now I’m freaked out thinking I may lose this or maybe there wasn’t anything to begin with. Anyone have this situation happen or have dates be this off?? Sos 😭