Default Something strange in Whatsapp

Hi,

Yesterday I had an strange problem with whatsapp. I received three messages but I had not read nothing until I arrived at home at night. When I entered in whatsapp, I realized that only two messages were marked as not read. It's very strange because I didn't enter in whatsapp in all day (only at night). I don't understand nothing. Maybe I have a ghost in my mobile that read my whatsapp messages?

Thanks a lot.

Regards.