check your "blockchain_headers" file and see if the file size is growing or not.
the file is located 1 directory above where your wallet file is located.
On Mac:
Open Finder
Go to folder (shift+cmd+G) and type ~/.electrum
http://docs.electrum.org/en/latest/faq.html#where-is-my-wallet-file-located

the file size should be 35.79 MB at first (downloaded from Electrum.org server) and then grow to 35.9 MB (37,675,008 bytes to be exact by the time of writing this). if it is not then it means you are not downloading the file needed for that "Synchronising..." status to go away. so check your internet connection and firewall.

you can also check your network window and see if it shows this number or not.