Thanks for the query.
Sometimes gestational sac
without fetal pole
will develop that is called as blighted ovum
In it the irregular sac can be seen. Possibly your doctor might have mentioned this.
The beta hCG levels will show some elevation even with blighted ovum.
So you better go for trans vaginal ultrasound
which can identify the exact the status of the sac.
And depending on that treatment can be taken.