Elevated CA125

I was diagnosed with stage 1C Ovarian cancer in Dec. 2001.  My pre surgery CA125 was only 38.2.  I received 3 rounds of Taxol and carboplatin and went on to participate in a study which gave me 24 1 hour weekly infusions of Taxol.  My CA125 has been at 7 since my first round of chemo and even dropped to 5 about 4 months ago.  Last week, May of 2004, I was told that my latest CA125 test was 20.  I retested and it came back at 17.  I realize that I need to wait and look for a trend in the numbers. My doctor has told me to wait 2 months to get another blood test and would give me a CT scan if I insisted, realizing that it could be clear (which would not necessarily mean anything).  My questions are these... Is waiting 2 months advisable?  Shouldn't I be tested every month? Would a follow up internal ultra-sound be reasonable to request?  And finally, based on my doctor's very passive response, should I be looking for another health care provider?  Thank you for helping me find some peace of mind.