How to prepare for family history questions?

My first prenatal appointment is Tuesday morning, can't wait :) but is there any info I need to know going in? I heard they ask a ton of questions about family history & im not sure what I even know about my family background, same with my bf. We aren't telling our parents until we get an ultrasound / hear a heartbeat so we know everything's okay so we can't exactly ask them questions. Help? /: