Blank civicrm?page=CiviCRM&q=civicrm/contribute/transact&reset=1 live contribution page wordpress
By testing on the wpmaster.demo.civicrm.org site and going to what i take it is the public version of the contribution page at eg


  http://wpmaster.demo.civicrm.org/civicrm/?page=CiviCRM&amp;q=civicrm/contribute/transact&amp;reset=1&amp;id=4


I do not get a blank page which suggests several things including that it isn't broken on dmaster. 

Some possible things to try


switching WP themes
using Inspect to compare output on demo v your site


Not sure how much either will help as not a WP specialist