You have an infestation in your house. You have to get rid of the eggs and larvae in your carpet or they will continue to hatch and you will never be flea free.
Petsmart carries Adams Carpet powder. It's the only one I have found that works. You have to work it into your carpet with a broom, then vacuum it up. I let it sit overnight and keep pets off it.
Farnam Adams Flea & Tick Carpet Powder w/Linalool & Nylar - Sale - Dog - PetSmart