How do I get an empty dateTime field from a SharePoint list?

I currently have a code that retrieves data from a custom SharePoint list. Part of the data that I am getting is a date field, and I am getting it by doing this...

DateTime myDate = DateTime.Parse(myItem["MyDateField"].ToString());

At first, this seems to work just fine. However I noticed that if there is no data in the date field, then a nullException reference is thrown. What is the best way to handle this, to return just a blank or empty date as the default once there is no data in the field. Thanks for the help.