uh huh. I almost did.
This was for my 20 week US with DS, I was doubled over in pain in the waiting room, tears streaming down my face, so they tell me to "try to let a bit out' WTF? There is no inbetween for me, its full or empty lol.

So needless to say this time I was a lot more restrained, and different u/s place too so different advice. Much better experience!