Nesting?

Bria sent me out to buy a sheet for our crib last week. I would ask if this might be a symptom of early onset "nesting" but then I remembered that we have had our crib set up for a few months now. Husbands, fathers: is this normal? If we are doing this now what will we be doing when she is seven months pregnant? Eight months? What if our little baby girls comes late?! I fear to imagine the consequences of such neonatal tardiness. Any feedback is welcomed.