I think there's that element with a surprise pregnancy or one that's taken a long time to achieve, that if you get the desired gender it will be 'worth it'. I felt like that with ds4 anyway, like there had to be SOME reason why it took 2.5 years to fall pregnant so it had to mean I would get a girl then all that waiting and hoping would have had a reason. (Of course we all know that all babies are worth it, but GD does funny things to the brain at those times when it's at its strongest)
Good luck anyway