My pregnancy was unplanned - I quit for five years then started again in the past year. I sat outside one lunchtime having a cig while waiting for my test to tick over to negative and got the shock of my life when the bfp turned up! I finished my smoke, went back to school (I'm a teacher), came home and chain smoked four more while I stressed on the phone to my bestie, and haven't had one since. It's not easy!
I don't know if these will help or not, but I will always crave cigs til the day I die. It is a daily thing for me, and I have two ways of coping. First, tell yourself that you are either a smoker or a non-smoker. If you have quit, then you are a non-smoker and therefore don't need a smoke! Second, remember that cravings only physically last for five minutes or less, and they get further and further apart. The first three days are the tricky bit, so have plenty of little things you can do that distract you for five. It gets easier every day. Good luck, and you can do it. Cold turkey is the way to go, IMO :-)