I kinda think, that if you feel that strongly about not wanting a particular gender, then you should maybe reassess your decision to have children.
I know that sounds super harsh, but allow me to explain. It's 50/50 as to weather you have a boy or a girl, some people end up with runs of just boys or girls and others end up with a mixed amount but realistically, it's a 50/50 chance.
In my family I have 2 brothers who were the exception to the rule as there are like 20 females in my family. All of those have gone on to have multiple girls and what did I have? A boy. Odds are that I should have had girls but I didn't. It's a 50/50 shot and we can't change or predict that.
If you get your boy, then great, you have what you want but what if you have a girl? Youve known from a young age that you dislike girls but what if you are told you have one on the way? I worry that the child would be treated with contempt and not treated as well as a boy would be by you - a fair assumption given your self explained dislike of girls.
I think you need to have a long think about what you really want given as you can't guarantee a certain gender and weather you can offer the child what they deserve to have should they be the 'wrong' sex.
In my experience btw, my son is 4, nearly 5 and he's a whiny wingy sassy ass monster at the best of times. Every child is unique and different and if you had a bit, believe me it does not guarantee that they will not have the qualities you dislike.
I hope I've not caused offence but as you've asked for opinions, there is mine.
