put aside the amount of cigarretes you want to smoke a day.. for example if you smoke a pack a day, put away 15, and smoke only them throughout the day, make them last the whole day, in a week, make it 10 cigaretes a day, then 5, then see if you can go without them.
i could never quit, i only smoked less when i felt nauseated from smoking, had 2 healthy pregnancies and babies, and know of plenty of women who smoked and had healthy babies, don't stress yourself too much over it.