It’s a risk, having a child for a preferred gender. No judgement, to be honest I was the same as you - both genders but with a preference for a particular one for the fourth- but I decided not to do it mainly because of the work and stretching myself too thinly, but also because although the other gender would have been loved and treasured just the same I know I would still not have achieved all that I wanted in the venture of having another child, and I didn’t want the wistfulness to be magnified (as I think I might have done) with the pressures of four.
A part of me still wants a fourth 
But personally I know I’ve reached my physical limit in dealing with three, so the decision has kind of been made for me.
Also putting me off is the concern of having a fourth with health issues. Again I would deal with it and the baby would be loved and cared for, but the extra work would mean my eldest two in particular would have to be short-changed.
In an ideal world I’d have a fourth, healthy and of my preferred gender ideally, and a couple of nannies to help with the school run and the practical side of things whilst I did all the fun things that would be my dream, but all that ain’t gonna happen 
On the other hand it could have been the gender I’d prefer but the work it would take even with the preferred gender would have overtaken the joy.