Where?
http://theconservativetreehouse.com/2015/08/08/trump-megyn-kelly-and-chris-wallace-had-blood-coming-out-of-their-eyes/
Video at link (need listen through to 5:25 to hear Chris Wallace eye’s comment)
Trump: Megyn Kelly and Chris Wallace Had “Blood Coming Out of Their Eyes”
Despite the twitter outrage the full context of Trumps remarks were in reference to Megyn Kelly and Mike Wallace’s questions and presentation. Trump said both Kelly and Wallace appeared to have blood coming out of their eyes.
I think you have to be a deviant to jump to menstruation, or more likely with a desire to damage Trump and a fertile imagination.