Emails from my inbox have been deleted

I opened my hotmail account today to find all of my emails from my inbox (excluding the ones that were flagged and about six of the most recent ones) deleted!!  My email account certainly has not been inactive (I check it very regularly) and it was changed to Outlook several months ago and nothing happened then.  It is only the emails in my Inbox that were seemingly affected, the emails in my folder are still there.