Google AdMob ads not showing up in my app

I am developing an app, as of now it is not released to the app store, and I wanted to add a button to show an ad when clicked. I setup my account this morning, and got all the code setup. It worked completely fine with the test ads, but as soon as I replaced the test unit ID with the real one, it didn't show the ad. I read somewhere that my account needs to be verified but I have now received the verification email from google saying my account is certified but still no ad. If you need any additional details feel free to ask!