whatever you eat your body gets used to.... so if you're only eating 29pp and no weeklies, don't expect to be able to go up to what your allowance "should be".
The human body is a clever thing, for the most part it adapts to what its given.. if you eat less it needs less. Worth keeping that in mind
here's a quote from a weightwatchers article on dieting myths (not all relevant to you perhaps but interesting nevertheless):
"6. The less I eat, the faster I'll lose
Wrong. "The less we eat, the slower our metabolism gets, and the slower we lose the weight," says Mandel. "Deprivation also makes us unhappy and actually causes us to overeat and overindulge." Increasing your caloric restriction in reasonable amounts can increase weight loss, but cutting back to an unrealistic intake will likely backfire. A slow and steady approach — including treating yourself to your favorite foods, in moderation — is your best bet for building a healthy relationship with food and reaching your long-term goals.
So stop telling yourself lies that sabotage your efforts. Instead, start living your life with a weight-loss plan that works for you. You'll feel better about yourself, your confidence will grow, and you'll keep the weight off."
I ate every one of my dailies and weeklies last week and lost 3.5lb...so its certainly not a detrement to weightloss. But you won't do yourself any significant damage as such... just won't make it easier in the future when you actually want some treats (believe me it does come!!)