Question for the board

I posted this in another forum and haven't gotten much response so I am trying here:

I was diagnosed with DCIS in Oct. '08. I had two unsuccessful lumpectomies because my cancer, while a grade 0 was multi-focal. I finally had a unilateral mastectomy in Feb. '09 and an implant placed on my "good" left side because I wanted to go larger.

I then had exchange surgery in June '09 and two subsequent revisions, one in Sept. '09 because I thought my reconstructed breast didn't have a nice shape and then in February '10 I had my implant on my good side fixed because it had somehow dropped.

So, after six surgeries for a non-invasive cancer and finally happy with the cosmetic results I thought it was over. I've been going for regular mammos, scans, even ovarian cancer scans as a precaution and all has been fine.

On Monday I went for a routine scan of my reconstructed breast (I still have my nipple). Anyway, doctor at the radiology place told me one of my lymph nodes was "plump" and she'd like me to have an MRI. She didn't seem concerned and said she thinks it's nothing but they wouldn't let me have the MRI until it was 8-13 days after the first day of my cycle bec. that's when they get the best pictures. 

So..... that would have meant weeks of waiting and I didn't think I could do that so I called my cancer surgeon who said that I could just do a biopsy if I didn't want to wait it out. He called the doctor at the radiology place and that's what they thought was best.

He reiterated that she was "not concerned". I go for the biopsy on Monday.

My question is - has anyone else gone through this? Does it seem possible I could have cancer in my lymph nodes when I had a mastectomy and only DCIS? I should mention they checked my nodes twice - once in November '08 and then again in February '09 and they were clear.

Any thoughts or opinions would be greatly appreciated.

Thanks!

Liz