My wife and I began Aikido one month ago, and I believe you will be studying at Jita Kyoei Dojo in Dallas, correct? We practice at a Jiyushinkai dojo as well (in Baton Rouge, LA), and I hear that Will (one of the instructors at your school) is a simply amazing teacher that really has a passion for teaching Aikido. Anyway, we were a little concerned about ukemi as well, but they really ease you into it. As a beginner, when I take ukemi, I still just find it cool as heck seeing how the techniques work! Just listen to your instructors, learn at your own pace (they all understand you're new), and I promise it will be fun!
On another note, we will be attending Clark Sensei's seminar at your dojo in October! Hope we can meet!
Train hard, stay on guard.