Definitely make sure of the points suggested, but know that while rare, this is not impossible.
Someone had this issue a couple of weeks ago here and in researching it, I found this http://allenbrowne.com/ser-40.html
Note that the page was last updated in 2015, and although at first it may read like it only applies to versions older than yours, 2013 is mentioned in the article.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.