It doesn’t make you a bad person for saying it at all. I’m having a boy and was the same. I’m very much a girls girl, like all my friends have always been girls and I’ve only grown up with a sister. Apart from boyfriends and lgbt male friends I haven’t had any typical boyish friends or brothers or whatever.
However I knew with my partner the odds of me having a boy were high. He’s one of four boys, most of who have had sons. His Dad and Grandad also only have brothers. And when I saw his 12 week scan I instinctively knew it was a boy from his pelvis and they confirmed this at the 20 week scan.
I was disappointed but also I’d had time to prepare myself as I knew there was a high chance anyway. And I’ve spoken honestly to people who had gender disappointment and they all said it disappeared as the pregnancy went on/baby was born. Which has definitely happened to me like
@raspberryjuice 
Now I just can’t wait to meet him and love him. Two ish weeks to go! If I have another it’s highly likely to be another boy too so definitely won’t be trying in the hope of having a girl lol as we’d be trying for a long time!