Special instructions before a pelvic ultrasound?

I've been having bad pelvic pain for about 3 1/2 wks now. I've seen a physician and she wasn't able to find the problem so she suggested I go to a Gynecologist. I don't have any health insurance so I'm pretty much going to need to pay cash for all of this. My mom told me not to go to the Gynecologist because she said I'm going to pay at least a $100 office consult for them to just tell me to get an ultrasound done. My mom works at a medical clinic and says that she knows someone that can do an ultrasound for me for free. Yesterday I asked my mom if I can for sure get an appointment for Wednesday and she said yes but said something about her needing to talk to them and find out what things I need to do before I get the ultrasound. I talked to her today and she said she hasn't gotten a call back from them. My question is... are there any specific instructions that I need to follow before I can get an ultrasound like: take certain meds, no eating, stuff like that?

Because I know my mom isn't going much out of her way to get this done, even though she knows I'm in a lot of pain, and I know by the time she does actually talk to them there will be some specific thing I need to do before I get the pelvic ultrasound and it will be too late for me to do it. I'm trying to get the appt. for Weds.

The above person is right....Drink plenty of fluids ,,,,,prior to exam and have a full bladder when you show up for the test....Water works the best, but if you are not a fan of water....Tea, coffee or drinks will do..

I also want to add that I agree with the fellow below....Get a doctors order and have the procedure done legally....It will be read by a Radiologist and if anything is wrong you will get the treatment necessary...

Ok, I do this for a living... I know I'm a guy but anyway... You need to see a doctor and have a pelvic exam and labs done first. They may have you get an ultrasound done, may not depending upon what the pelvic and labs show. If they do order the u/s, you will be asked to drink approx. 32 ozs. of water one hour prior to your exam. Don't worry, they will let you empty your bladder immediately after the exam. I know your worried about the money but your could go to either a family planning clinic or county health office and they could help with the cost. Please don't wait, while I do hope this is nothing it could be something that requires immediate attention.

P.S. Any one who would do an exam "under the table" should lose their job. On the other side, it takes a radiologist to read the exam for the gynocologist and without an order for the exam, that won't happen.