Yes it's too late. On their website they say more than 6 weeks PP you should just go for a traditional compression garment (such as a tank top). FWIW I used the belly bandit for the first two weeks, and I do think it helped tremendously, but I am still left with a small gut that I know will only be going away with diet and exercise.
Re: Too late for Belly Bandit?
I don't think you should waste your money. Those things are just like any other weight loss-type of fad product.
I had the belly bandit and it was ok. I am now using this and LOVEEEE it and it is only $35 (sorry not sure how to make it clicky)
https://www.amazon.com/Squeem-Magical-Lingerie-Compression-XL/dp/B000QWA2I2/ref=sr_1_1?ie=UTF8&qid=1298936691&sr=8-1