Dear doctor, if i want a boy pregnancy, not girl, could u explain me? and if i want a girl pregnancy, not boy?

? Of ethics and cost: check the following link http://www.babycenter.com/0_choosing-your-babys-sex-what-the-scientists-say_2915.bc

U get what U get: The sperm that reaches the egg first determines the sex of the baby.So it is the male, not the female that determines sex.There is no diet/position/timing that changes the odds.If you have lots of money you can try embryo selection and implantation via a fertility center.Even at this extreme there is no guarantee it will produce a healthy baby boy.