Video displaying large white margin above it when inserted as the first item on a post

Hi 7th Queen,

I want a video to be the featured image in a post. Is there a way to do that without a plugin? I can’t seem to insert a video as the top-most item on the post without an annoyingly large white margin at the top.

1. I don’t want a featured image on the post and then the video below it. I want the video to be on the very top of the post. But when I insert the video a large white margin sits above it on the page.

2. When I use a plugin to show the video in place of the “featured image”…the white margin still shows up. You can see it in this link: http://preview.carpooltoschool.com/traffic-congestion-safety-mobility-autonomous-vehicles-solving-the-most-pressing-transportation-problems-in-48-hours/

Thank you,

Jessie