Windows live mail doesn’t show anything new

I'm running windows live mail on a 64-bit laptop running Win7.  I have changed no settings or installed or deleted any programs, but for some reason Friday was the last time I got new mail in my dedicated mail program.  I still can send and receive mail from live.com, and on my phone - but nothing happens in my actual mail program, it's as if it's frozen in time on Friday afternoon.  Just to test, I composed and sent an email to myself from the mail program.  It never showed up on the mail program, either in the inbox or sent, but showed up in both places on live.com.  I can't figure out what I did or can do to fix it, so please help!  Thanks!