@Sofia254 I'm glad the host got back to you and your mind is now at ease. Try to keep in mind that in this day and age of texting, whatsapp, etc, people, especially younger ones who have grown up with this technology, often are expecting an instant reply. However not everyone uses a smart phone, apps, etc. I only access my airbnb account on a laptop and only check it once a day, as I am busy working, nor do I have unlimited data, so my computer is not just on all the time, alerting me to a new message.
I remember reading a post on some dating site years ago where a guy was asking other users to look at his account to see if they found anything wrong with it because he wasn't getting any hits. Another user asked him how long he'd had his ad up- he replied 10 minutes! He was actually worried because he somehow expected that tons of girls would instantly contact him as soon as he posted his ad.
It's great that you're the kind of person who wants to have all their ducks in a row (an expression you may or may not be familiar with) before setting out on a trip so as to minimize any nasty surprises- hosts love guests who are organized and communicative. But your Tuesday arrival ( 4 days away) may have said to the hosts that there wasn't any immediate urgency in responding, like within the first hour, or even half a day.