I am retired and divorced. My 10yr old son lives with me over 6 months, so I changed my status to head of household from single. I wonder if that delayed my refund?

If you claimed the Earned Income Tax Credit or Additional Child Tax Credit (refundable credits), which is quite possible with a ten yr. old son, your return will not be processed until Feb. 15th.  Filing the Head of Household Status alone won't hold up your return, but taking either one of those credits will.