Femara

I have low-grade ovarian cancer and I started on Femara about six weeks ago.  My first CA-125 since starting it came back 20% higher.  The doctor said not to worry yet, it can take up to three months for it to fully kick in and start working.  I was wondering if anyone else out there on Femara (or another aromatase inhibitor or even tamoxifen) has had this experience of an increased CA-125 and gone on to see it work for them?  Any other words of advice about this type of treatment would also be much appreciated.