Hi T., It may not come off while nursing. I am a mom of two (a 3 year old and 10 month old). With my daughter I did not starte loosing weight until about 3 months after I stopped nursing and now with my baby I just stopped nursing him about 6 weeks ago and have started to notice a small budge (about 2 lbs). I believe it has something to do with the hormones your body produces while nursing.
See I was training for a marathon all fall 2007 while nursing my son- and not one pound was lost!!! Now that tells you something. I called my friend who is a GP Dr. and she told me that some women become hypothyroid while nursing which corrects itself 12-18 weeks after nursing is completed.
I know its not real advice, but I wanted you to know you are not alone and you can really drive yourself crazy worrying about it and even running a marathon won't work right now.
So please be patient (I know it is hard-trust me at about 6 months I broke down with sheer frustration) but my husband really was supportive and told me to hang in there.
Email me if you want to chat.