Hi,
Often a soft uterus is a sign of early pregnancy. If he got a negative result but a soft cervix he may have set up the ultrasound to determine if pregnancy is the cause. While a soft cervix is a sign of early menopause if this sounds unlikely she may simply have a low number of pregnancy hormone in her system and giving a false negative.
At this point it would be impossible to know for a fact with out the ultrasound. I would recommend she keep the appointment and she should know that day if she is in fact pregnant.
Walter
If you are satisfied with my answer please click the *accept button* so I receive Credit for my answer.
**Please consider leaving feedback about me!**