Can i check or preview the ad I have created before sending the ad tag to serve?

Yes.  You can preview the ad that you created before sending the ad tag to serve.

Step 1: Login to http://www.mobileads.com. Click Manage Campaign and click the View Ads link  of  your campaign.

viewads

 

Step 2: Click Preview link of the ad. And click Get Ad Tag button.

 

getadtag