CEA Levels Bouncing?

I have had Cervical cancer and most recently 2007, rare Tubular Breast Cancer w/mets to the lymph nodes.  My CEA count at the time of the breast cancer, 2007, was only 3.6 ( and I am a smoker).  The CEA levels have been rising, but sometimes bounce around from 8.0 to 5.2.  My doctor says not to worry until the CEA is in the double digits, however, my body does not react as normal.  None of my nodes were ever enlarged, actually they were abnormally small, even w/cancer, and upon diagnosis, the CEA was only at 3.6 so I am worried that I may still have cancer that may be undetected?  Is is normal for the CEA to bounce around?
  I recently had a colonoscopy and endoscopy where we found pre-cancerous polyps that were removed, in both the upper and lower intestine, and they found a fissure with displasia in the anal areas.  Although no biopsy was done in this area to determine if the displasia is high grade or low grade.  Should I be concerned?  I've had a FOB (?) tests which resulted in positive for blood in the stool, and I am still having lots of blood when I go to the bathroom, even after the polyps were removed.  Is this normal?  What else should I do or what else shold my dr do?