Peg,
I am going to go with what Curious has stated. I had a total hysterectomy about 8 years ago. To make a long story short I have a cystocele and rectocele and it CAN cause the bladder to spasm. I have been graded out as a Grade 1; which basically means...no surgery or repairs warranted yet. So, I do pelvic floor PT which has helped considerably. Just a thought and I hope your ultrasound turns out okay.