T.L.
Being a nurse and a mother, I know the whole just put a catheter in to get a urine sample sounds horrible and I did not want to do that when my daughter who was also about 18 months when she got a bladder infection. So, if possible you should call the office today and see if you can get a urine bag that has adhesive around the top to adhere to her vulva to catch the urine when she goes (this will all be inside her diaper). You will also need a sterile specimen cup to transfer the urine into to bring to the lab for testing. You will need to make sure she is cleaned properly down there before putting the bag on. Hopefully the doctors and nurses will work with you on this one and let you do it this way instead of the catheter, but if not the catheter should be quick, it's just more traumatic for the little ones :(