Went to the doctor so I could get my IUD taken out my string want visiable so I have to get a ultrasound to see where it is what will the doctors do?

Usually easy. Most of the time this is not a big deal. The iud strings which are usually hanging out of the cervix have gotten pulled up inside the cervix but the iud is still in the normal location. Most obgyns have an instrument called an iud hook which can be used to remove. Sometimes we have to look with a camera called a hysteroscope to find the strings. Very rarely the iud is not present in the uterus.
IUD. A ultrasound for evaluating iud placement is very simple. It will be done transvaginally. They want to make sure the iud is in the endometrium and that it has not migrated. Many ultrasound machines also have 3d capability to confirm the placement.