R.N.
I agree with Denise, get used to it. I have run into this more and more over the years. My older son is 9 and there is always someone who doesn't rsvp but shows up, then the ones who say they are coming but are no shows. Try to be flexible, you can't change the way some people were brought up. I was taught it's terrible manners not to rsvp but other people see it differently. Also, you have a few days yet, you will probably get a good number of calls at the last minute (or the day after the rsvp date). I think it is ok to send an email to people who haven't responded a couple days after the date to get an idea for food if you have a lot you have not heard from. I wouldn't bother calling everyone. A blanket email is less trouble and less awkward. Try not to worry about it until it's the $50/plate sit down wedding reception that they haven't responded to.