Appendicitis CT Results???

Hello everyone,
If anyone has any advice on this I would greatly appreciate it. I am a 29 year old, 102 # female (thin from being so ill). I have been having appendicitis symptoms for 6 days now. Pain in the lower right quadrant, radiating back pain, right groin pain, nausea, no appetite, pencil-thin stools, and a low grade fever. I had a CT scan which read "The appendix cannot be specifically visualized, and also there is a trace of free fluid in the pelvic cul-de-sac." From some online research I know that CT scans on thin people are harder to diagnose from the absence of a lot of belly fat. But what is this fluid???? The doctor told me that they were 90% sure it isn't appendicitis, but the report was inconclusive so how can they rule it out? I also have been having terrible pressure in my bladder and a lower bloated abdomen. Is the appendix related to bladder symptoms? I have an appointment with a surgeon in 4 days. I am very scared. I have had my gallbladder removed almost 7 years ago and wish that they would have taken the appendix then too. Does anyone out there have a similar experience with these awful symptoms? Thank you in advance.