I think you have every right to ask people not to visit until you are ready. We did. I was initially booked for a c/s (placenta praevia) and our plan was to not even tell anyone when it was booked for and announce the birth after it happened. As it turned out, I went into labour naturally, had emergency c/s, bubs born 4:42 in the morning, we rang our immediate family 4 hours later and told them they can come visit after 3pm. Everyone else we told that night or the next day. As far as I know, no one was offended or upset.