We don't say that having a girl is wrong or anything, but for the couple who really want to have a boy, Dr. Shettles has a few tricks for them. In his book "How to choose the s3x of your baby", he has mentioned those tricks. He has over 50 years of experience in IVF and he explains his theory that how X and Y sperms are different from each other.
There are two types of sperms, one has X-chromosome and the other has Y-chromosome. When X-sperm fertilizes an egg, a baby girl is born and when Y-sperm fertilizes an egg you get a boy. According to Dr. Shettles' research boy sperm that is Y-sperm is somewhat weaker, smaller and hence faster than girl sperm. But girl sperm that is X-sperm is more resilient and survives longer inside the female body.
Its all about timing. Y-sperm being the faster reach the fallopian tube before X-sperm. But if the woman has not yet ovulated then Y-sperms wont find any egg to fertilize. Sperms can't survive longer in the fallopian tube, so Y-sperm will die soon. And by the time the woman has ovulated the more resilient X-sperms will be left to fertilize the egg. Hence giving you a baby girl.
So now you know having a right timing can make you a proud parent of a baby boy!!!