Should I be worried?

I am a 28 year old female.  About a week ago, I started having rectal pain.  Not really pain but a little pressure.  I went to the doctor and looked up my rectum with a light and found that my colon was bleeding just a little.  I assume that it was light red blood, not dark red.  Anyway, he told me that it was colitis.  He gave me some meds to take for 2 weeks and then come back to see him.  I went ahead and made an appt to have a colonoscopy done on 9-3.
My question is..has anyone that has had colitis ever had these symptoms, or should I be worried that I have cancer or something.  I am terrified that I do.  I can't even sleep at night. So, could someone please help me?
Thanks

[RTFLY]

Hi...first of all, as a former sufferer of ulcerative colitis I want to tell you to please relax. DO NOT diagnose yourself with cancer! Bleeding in the rectum can have more than one cause. Colitis is not cancer. See what your scope says and then get back to us. I will be more tha happy to talk with you about meds/causes/treatment of colitis. Been there...done that! Good luck and take care...
                                  JCI

[jillybean]

Did you have any of these symptoms.  I am really scared.  I don't know why.  I know that the chances of me having cancer is very slim.  But, I thought that colitis caused diarhea (diarrhea).