5 week 1 day ultrasound

brittany

Today I had an early ultrasound and I know the day I ovulated on cycle day 32 I believe which would put me at 5 weeks 1 day, last period would put me at 8 weeks and 5 days I believe. But my ultrasound has me measuring at 6 weeks 4 days all we could see is the yolk sack anyone else have this happen?