Hi Andy,
Checked the code of my website and found that the twitter:card markup code is still there. The code is as below. Please, let me know if there is anything wrong with it
<b:if cond='data:blog.pageType == "item"'>
<b:if cond='data:blog.postImageUrl'>
<b:if cond='data:blog.metaDescription'>
<meta content='summary_large_image' name='twitter:card'/>
<meta content='@shaanhaider' name='twitter:site'/>
<meta content='@shaanhaider' name='twitter:creator'/>
<meta expr:content='data:blog.pageName' name='twitter:title'/>
<meta expr:content='data:blog.metaDescription' name='twitter:description'/>
<meta expr:content='data:blog.postImageUrl' name='twitter:image:src'/>
<meta expr:content='data:blog.homepageUrl' name='twitter:domain'/>
</b:if>
</b:if>
</b:if>