I submitted my plugin for approval on 17th May. However, after doing the Upload and Submit. The page just reloaded without any kind of message. Can I know for sure that my plugin has reached the reviewers ? It seems to me I can make another submission for the same plugin and that makes everything quite confusing.

Make sure you zip only the source code of your plugin i.e the directory which contains your "Plugin.php" file, not the vendor name folder in your plugins directory. For eg. If Plugins > YourName > YourPlugin > SourceCode is your directory structure, select all files consisting of SourceCode and zip it. Don't zip YourName folder or YourPlugin folder. Upon successful submission, you will see a notification on screen after reload and the "Approval" menu option will change to "Update".