simple questions, complex answers

Since me and the last girlfriend broke up about 6 months ago Ive been dreading dealing with meeting a new girl for the simple fact that I anticipated having to have a conversation about my family and particular my brother. Because its tied to a relatively simple get to know you question which often comes up early in any courtship as to better understand who the other person is. Its just an awkward subject to broach on a first or second date, It happened last night at a bar with a girl whom I really like. She simply asked if I had any brothers or sisters to which I paused for a moment and then replied no. Which I instantly regretted for so many reasons, I felt like a liar, but more importantly I felt like I was doing my brother some injustice. Maybe its because I was in a loud bar and didnt think it was the place to have the conversation or maybe it was to soon, or maybe I just took the easy route out. The night went great and I will definitely see more of this girl but I cant help but feel racked by guilt for my omission. I have considered all the options, I could have said yes I have a brother, but that would lead down a painful path of questions regarding what does he do how old etc... I cant help but feel I took the only route I had. This may be one of the many aspects of getting to know my new life, the new me.