Can the pregnancy sac change shape as pregnancy progresses

[EdandNed]

Just that really.

Im 6 weeks today
Had 2 different scans within days of each other... 1 at 5+3 and 1 at 5+6
Yolk sac has got bigger, and can now see a foetal pole (couldnt in first scan) and overall the sac has grown by .6mm in 3 days.
The scans were done at 2 different departments but the dimensions differ and although the sac is bigger in some areas, in other areas its smaller
So can the sac change shape at the pregnancy progresses?

Sacs always look different depending on whether it was an internal ultrasound or an external one, also how much you drink affects the size etc (I'm having twins and the shapes have varied hugely) also no 2 sonographers will measure the same so there will always be some variation in the measurements

Ok, im so nervous.
Im bleeding as well which obviously isnt helping my anxiety. I bled in my successful pregnancy which obviously ended well.

Ive been over analysing everything and was worried the smaller measurements were indicating that something was wrong.

Sorry you’re going through this. Agree with PP re measurements. Just wanted to say that you should be really encouraged by seeing a fetal pole on your second scan, and also that you really should try to wait at least a week between scans (unless symptoms change a lot) because the variation in measurements means it can be hard to interpret scans done closer together. Generally it’s even better to wait 2 weeks (which is why lots of EPUs book 2 week follow ups) but i know first hand how impossible it can feel to wait that long!
Good luck.