Redirection problems after moving WordPress

Hello,
I changed my wordpress to a subdomain (from http://www.mywebsite.com to blog.mywebsite.doc). I followed that tutotiel. But I’m not sure about point 10, and I didn’t do next points because I didn’t understand :/ But my site was “new”, so all the article will be deleted, I don’t need to keep them (only test purpose).

Unfortunately, when I go to the main page, I’m automatically redirected to the former domain, with nothing now. The other pages work, I can acces to them, as the admin panel.

Here the .htacess, if it’s helpful :

RewriteEngine On

	## www -> no-www
RewriteCond %{HTTP_HOST} ^www\.(.+)$ 
RewriteRule ^ https://%1%{REQUEST_URI} [R=301,L,NE,QSA]
	## http -> https
RewriteCond %{HTTPS} off
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L,NE,QSA]
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Thanks in advance for your help!