When you start your 2000 Ford Expedition in the morning it generates blue smoke that lasts about 5 seconds what is wrong?

Blue smoke is definitely oil, but the amount needed to produce smoke is so small that you'd not notice it on the dipstick. I suspect valve seals are getting worn out although it seems a little premature. I would wait a while, see if it gets worse before taking action because the cost of repair outweighs the annoyance at this point.