Kellie I decided with this pg that I was desperate not to put on as much weight as I had with m DD because I hadnt lost all the baby weight, or the 20 kgs I needed to loose before that, so I asked at the hospital to see their dietician- as I was going public I got to see her for free. I am now 40+ weeks and I have only put on 7 kgs for my entire pg, and I am as pleased as punch with myself.
So I can really recommend getting the support of your Dr's and a dietician, as for me it helped to keep me honst.