I would strongly suggest that going forward you post one article on your blog and submit a different article about the same topic to EZine. And if you want to submit articles to 3 article submission sites pointing back to the same post, I would suggest all 3 submitted articles be unique and different from the blog post they post to AND different from each other... So 4 articles would be required. Even though your blog post is likely currently seen as the originator of the content, things can happen (like if your site should be down at some point in the future for an extended period of time) that can cause Google to get confused and possibly start considering the EZine article as the originator. Hopefully, on the EZine version, you included a link back to the original blog post. That will help Google in determining the original. However the EZine article will now get flagged as duplicate content so it's content is going to be devalued which means it's relevancy scores will be much lower than they would have been if it were a totally different article. What you've done so far isn't necessarily "harmful" to your site yet... but you're definitely NOT getting the most bang for your buck... err... backlinks!