I'm on WW and breastfeeding. You do have to wait until bubs is 6 weeks before starting. They calculate your extra points based on factors like your starting weight, activity level etc. I started on 30 points which is so much food it is often hard to actually eat that much.

They are pretty strict with the rate at which you loose weight. A healthy aim is no more than 500grams a week so as not to compromise your supply.

HTH
Good luck
Spring