@Meganathan, Mine also expired, see this thread for what I did, Renewing expired free SSL certificate it was easy to renew/reinstall the SSL certificate. My existing certificate expired February 22nd, I did the renew/reinstall on Feb. 7th, doing it early I had two valid SSL certificates for my site for 15 days.
The first one expired on Feb. 22nd, the only issue with renewing it early on the 7th was that the new one expires on May 7th, 2020. Had I waited until closer to the first one expiring it would have been cleaner, but being the first time for me renewing the SSL I wasn’t sure how long the process would take. My site was still https, but with two valid SSL certificates until the first one expired.