First, good luck on getting the OK from your doctor! My daughter is almost 3 months old, and she is the best thing that has ever happened to me! The day she was born was better than anything else I had experienced- my wedding day included

I know that you are not allowed to attend meetings and weigh in while on WW, BUT I would talk to your doctor about it. When you are pregnant you only need a few hundred calories more each day, and I would think that this would be about the same as the WW program I am following now that I am nursing. (It gives you 10 extra pts per day.) This is for weight loss though, and your doctor probably won't want you losing weight during pregnancy.
I would not advise just eating whatever you want, though. I just ate whatever I wanted during my pregnancy, and with that and my high blood pressure I ended up gaining about 45 lbs. Lots of it came off in the 2 weeks after she was born, but then it started to come back again since I had rebuilt my bad eating habits!!!
Anyway, I would say discuss it with your doctor and hopefully you can come up with a plan!
Good luck, I hope you get good news!
Tara