I was in the same position as you with my 3rd pregnancy. I too had very strong girl vibes at the beginning of my pregnancy and had I heard girl at my 20 week scan I would have been sooooo excited and would have spent the remaining months planning and shopping and in a whirl of disbelief and happiness.
But I feared my GD, of hearing boy again so I chose not to find out. I also wanted to experience the big delivery room surprise, especially since I was having a c/section. I kept thinking of how I would feel and react if a girl popped out!
However, once the big scan was gone the feelings of pink faded and I became almost certain it was a boy, part of it was self-protection, I figured if I thought it was a boy I wouldn't be disappointed if he was. I also just couldn't imagine I would be lucky enough to get a girl. It seemed an unlikely dream.
So by the time of my birth I was pretty firm about my boy. Took a blue outfit, had spent the last few months thinking of my Edward and coming to terms with him and...out popped my girl! My reaction wasn't what I was expecting, I looked at her and thought 'that isn't Edward'. I had so built up this baby in my mind he was real and it was a shock not to see him. I didn't immediately bond with her becuase she seemed so alien - a girl - how could she possibly be mine!! Once people realised and brought me pink and I'd had time to get my head round it I was of course absolutely thrilled and I'm so happy and grateful to have her but I'll never forget that first day and how weird it felt. Also, instead of being able to plan and buy at lesuire I felt pressure to buy clothes and items I might not normally have chosen, especially as I was laid up and couldn't shop properly.
This time I'm definitely finding out. I want that time to prepare myself properly for the baby. I know if I hear boy at the scan I'll feel slightly disappointed (I'd like to give DD a sister) but I also know it will pass as I prepare for the baby I know is in there, rather than one I'm unsure about.
I think my reaction is probably unusual and not one I would have every anticipated. But yes, waiting for me was a bad idea!