By lmp I should be 9w3d, but an ultrasound today said 6w3d. Dr said no signs of concern at this time have to go back next week for another ultrasound. Could there be that big of a difference and baby still be ok? I had my period may 5 to 8, no period in June or July. Ovulation date according to glow was May 19. (Didn't test for ovulation in any way) Anyone have this happen and everything was ok? And is it strange to measure exactly 3 wks behind what my lmp puts me at?