Congrats, dude! So nine months ago, you walked into the bedroom and said, "I'm Rob Base and I came to get down!"
I can't believe this is your fourth kid and you're asking this. Yes, it's normal to be asked that question. In my experience (three kids) it's only uncomfortable to field that question when you haven't decided. Our third wasn't named until after we'd been home for twelve hours and we'd spent three days in the hospital after her birth, so she existed for nearly four days being called only "baby."