After you enable SSL on your site, you'll notice that your social share and like counts reset back to zero. This is due to the way these metrics function after a 301 redirect.
When you enable SSL on your website, your site's protocol will change from http:// to https://. Social network sites will crawl your original non-secure http page, and then will update their share and like system to your new secure https site after they detect the 301 redirect. Due to this permanent redirect from your insecure protocol to your secure protocol, your social share and like counts will reset for your new site.
Please note: if you're comfortable working with code, you can edit your blog template to add the parameter "downgrade_shared_url=true" to the "blog_social_sharing" HubL tag. This will send the http URL, not the https URL, to Facebook and preserve the like counter during the switch to the https URLs. Please keep in mind, however, that you'll need to update your blog template to add this HubL tag, and it modifies all URLs sent to Facebook for all blogs using that blog template.