Wedding Message To Put On A Card Has Anyone Had Problems With Wedding RSVP's?

Has anyone had problems with wedding RSVP's? - wedding message to put on a card

I have my wedding invitations, there are about 3 weeks and 140 over 15 who replied! Now there are a few close family, I think it will have certainly there, but not yet responded, the event. I do not know if they have guests or what? The left one week, but I'm so nervous that I was planning this big thing, and it's like 30 PPL. People normally do not RSVP and still? The family of my friend is more than half off, and no one answered, but they all appeared at the wedding of his sister last year with a period of 8 days! Is it so difficult to put a letter in the mail? If so, they can also do it on our website! It is very frustrating.

It would be bad taste to send an e-mail message or Facebook remind people to RSVP? I really do not want to draw 100 people, 2 weeks before the wedding. I have to do one million things already: (